Use custom hostname when applying remote config

[r33drichards]

Hey there! I am using comin to manage my nixos dev environment and I ran into the following scenario

My nixos flake is defined with the hostname "hello" and my networking hostname is "dev". When I try to apply the configuration with comin, comin uses the networking hostname which does not exist on my config, thus failing. This changes adds a config option to configure hostname in the service, so that it applies the correct hostname when updating.

This could also work as a per remote config but I didn't see an obvious way to do that from my limited view.

Figured I'd contribute this back since it immediately unblocks my use case.

[nlewo]

Hello @r33drichards!

I am using comin to manage my nixos dev environment

I'm glad to meet the second comin known user! So, thx you for giving it a try :wink:

Thanks for your contribution.