This is the same as the feature already present in the launcher and
connection settings. Not sure how much sense it makes for systemd services
as they run rather independently from the UI but maybe it is useful.
* Allow to pause all devices on metered network connections (devices will
be automatically resumed when network is no longer metered)
* Allow to stop Syncthing when it was started via the built-in launcher
on metered network connections (it will be automatically started again
when the network connection is no longer metered)
* See https://github.com/Martchus/syncthingtray/issues/231
Not sure why I'm getting
```
Fehler beim Abfragen der Syncthing-Konfiguration: Error transferring http://127.0.0.1:8384/rest/system/config - server replied: Forbidden
URL der Anfrage: http://127.0.0.1:8384/rest/system/config
```
one one of my setups but this kind of error can likely be ignored shortly
after the start similar to other types of errors.
When stopping the Syncthing service ourselves we can apparently also
get "connection refused" and not just "remote host closed". So this
kind of error should be supressed as well.
Martchus
John Veness