Code review comment for ~danilogondolfo/network-manager/+git/network-manager:new_autopkgtests

I'd like us to make sure that this test-case (from bug #1952967) is also supported (doesn't need to be using "nmtui", though):

> To test one can launch nmtui with the following command:
> network-manager.nmtui and then:
> - Proceed to add new connection
> - Select "IP tunnel"
> - enter a profile name e.g. "IP tunnel connection 1"
> - enter a device e.g. "gre10"
> - select mode "GRE"
> - enter local IP e.g. "10.20.20.1"
> - enter remote IP e.g. "10.20.20.2"
> - Press "OK" to save the connection