I'm managing a host with propellor that is booted up perhaps once per week at random times (it's my grandparents' machine).  I have it running propellor with a cronjob in the standard way, pulling from a git repository, so I can update its configuration by pushing PGP-signed changes to the centralised git repo.  Now, I would like to change the URI of the centralised git remote.  Can I just write a `cmdProperty` that sets the new URI on the repo in `/usr/local/propellor`?  As described, I can't simply --spin the host as I never know when it's online.
