[Merge] ~aleasto/software-properties:gtk-no-daemonic into software-properties:ubuntu/master

[Alessandro Astone]

It's not much of a documentation, but I guess this is it: https://lazka.github.io/pgi-docs/Gio-2.0/classes/Application.html#Gio.Application.do_shutdown
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https://code.launchpad.net/~aleasto/software-properties/+git/software-properties/+merge/483389
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