Right now we set a subtitle of "" when the port is invalid. This
leads to the "Port" title getting center aligned vertically.
We also keep the port sensitive even when it's empty and there is
little value in copying it.
This commit changes the subtitle to " " so it serves as a
placeholder to keep the "Port" title top aligned. This commit
also makes the port insensitive in that case so the user never
copies the placeholder space.
Closes: https://gitlab.gnome.org/GNOME/gnome-control-center/-/issues/2934
The code currently assumes that if the fingerprint is non-null it's
valid, but gnome-remote-desktop can also set the fingerprint to an
empty string if there's no certificate yet.
This commit makes sure to handle both NULL and empty fingerprints.
If the username and password get set then the certificate fingerprint
isn't updated even if that lets the service start.
This commit fixes things by doing a round trip through the service after
setting the username/password to
1. Make sure the change actually worked
2. Trigger our fingerprint dialog setting code that currently only runs
on reading username/password
