Welcome dialog offers to open preferences window

[orontee]

Context

At present time, when starting Argos with its default configuration, a local service is used. If connection fails, the "welcome dialog" pops-up and recommend to tweak the base URL of the Mopidy server.

It would be more helpful to direct users to the preferences window once they have read the recommendation.

Analysis

Check the return value of the dialog run, and activate show-preferences action depending on that value.

To test:

matthias@peitho:~/Projets/argos$ flatpak run --devel --command=sh io.github.orontee.Argos
[📦 io.github.orontee.Argos ~]$ gsettings get io.github.orontee.Argos mopidy-base-url
'http://192.168.1.45:80'
[📦 io.github.orontee.Argos ~]$ gsettings reset io.github.orontee.Argos mopidy-base-url