[GNOME] Enable “Audio call” (no video) to be set as the default call method

Issue generated from Tuleap's migration script. Originally submitted by: Óvári (ovari)

Enable “Audio call” (no video) to be set as the default call method on:
The GNOME client for Ring.
Liberté, Égalité, Fraternité - Version 1.0
built on 2017-07-28 06:42:04 UTC

Please advise if you need more information or when this has been updated to test.