appFavorites: Check for renamed ID when adding favorite
In cases, where there exist two desktop files for a single app that also correspond to the ones in the rename table entry (as is the case in Ubuntu with, e.g., gnome-terminal), adding the app as a favorite results in both desktop files appearing in the dash (but not in the settings string). That can be fixed by performing the same check as in reload().
Fixes #471 (closed)