When I `propellor --spin HOST`, I started to get this warning:

```
** warning: git branch origin/master is not signed with a trusted gpg key; refusing to deploy it! (Running with previous configuration instead.)
```

Here's the relevant output from propellor:

```
Preprocessing library for propellor-5.9.1..                                                                                                                               
Building library for propellor-5.9.1..                                                                                                                                    
Preprocessing executable 'propellor-config' for propellor-5.9.1..                                                                                                         
Building executable 'propellor-config' for propellor-5.9.1..                                                                                                              
Propellor build ... done                                                                                                                                                  
[master ee86ede9] propellor spin                                                                                                                                          
Git commit ... done                                                                                                                                                       
Enumerating objects: 1, done.                                                                                                                                             
Counting objects: 100% (1/1), done.                                                                                                                                       
Writing objects: 100% (1/1), 869 bytes | 869.00 KiB/s, done.                                                                                                              
Total 1 (delta 0), reused 0 (delta 0)                                                                                                                                    
To [redacted].com:sr/propellor.git                                                                                                                      
   ed5038fa..ee86ede9  master -> master                                                                                                                                  
Push to central git repository ... done                                                                                                                                  
gpg: encrypted with 4096-bit RSA key, ID 0x[redacted]0F5, created 2016-09-06                                                                                          
      "Siddharth Ravikumar <[redacted]@[redacted].com>"                                                                                                                      
From [redacted].com:sr/propellor                                                                                                                        
   ed5038fa..ee86ede9  master     -> origin/master                                                                                                                       
Pull from central git repository ... done                                                                                                                                
gpg: Signature made Thu Apr  9 09:09:25 2020 EDT                                                                                                                         
gpg:                using RSA key [redacted]                                                                                               
gpg: /usr/local/propellor/privdata/trustdb.gpg: trustdb created                                                                                                          
gpg: Good signature from "Siddharth Ravikumar <[redacted]@[redacted].com>" [expired]                                                                              
gpg: Note: This key has expired!                                                                                                                                         
Primary key fingerprint: [redacted]                                                                                              
gpg: Signature expires Fri Apr  9 09:09:25 2021 EDT                                                                                                                      
** warning: git branch origin/master is not signed with a trusted gpg key; refusing to deploy it! (Running with previous configuration instead.)                         
Sending privdata (5352 bytes) to cygnus.[redacted].net ... done                                                                                                        
From .                                                                                                                                                                   
 * branch              HEAD       -> FETCH_HEAD                                                                                                                          
Sending git update to cygnus.[redacted].net ... done                                                                                                                   
Pull from central git repository ... done                                                                                                                                
gpg: Signature made Thu Apr  9 09:09:25 2020 EDT                                                                                                                         
gpg:                using RSA key [redacted]                                                                                               
gpg: /usr/local/propellor/privdata/trustdb.gpg: trustdb created                                                                                                          
gpg: Good signature from "Siddharth Ravikumar <[redacted]@[redacted].com>" [expired]                                                                              
gpg: Note: This key has expired!
Primary key fingerprint: [redacted]
gpg: Signature expires Fri Apr  9 09:09:25 2021 EDT
** warning: git branch origin/master is not signed with a trusted gpg key; refusing to deploy it! (Running with previous configuration instead.)
Preprocessing library for propellor-5.9.1..
Building library for propellor-5.9.1..
Preprocessing executable 'propellor-config' for propellor-5.9.1..
Building executable 'propellor-config' for propellor-5.9.1..
Propellor build ... done
cygnus.[redacted].net has Operating System (Debian Linux (Stable "buster")) X86_64 ... ok
cygnus.[redacted].net standard sources.list ... ok

```


The gpg key in question is not expired and the secret key for it is available on the machine from where I'm doing `propellor --spin`:


```
 gpg --edit-key '[fpr redacted]'
Secret key is available.

sec  rsa4096/0x[redacted]
     created: 2016-09-06  expires: 2020-09-02  usage: SC
     trust: ultimate      validity: ultimate
ssb  rsa4096/0x[redacted]
     created: 2016-09-06  expires: 2020-09-02  usage: E
[ultimate] (1). Siddharth Ravikumar <[redacted]@[redacted].com>
[ultimate] (2)  Siddharth Ravikumar <[redacted]@[redacted].com>

```

Any idea why I'm getting the warning about the branch not signed with a trusted a gpg key. How should I resolve this issue?

