[gnome-music] (3 commits) Non-fast-forward update to branch cherry-pick-51df37f9

[Marinus Schraal <mschraal src gnome org>]

The branch 'cherry-pick-51df37f9' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  e7ab7f6... notificationspopup: Fix source not found warning

Commits added to the branch:

  3a1daf5... flatpak: Allow GNOME media keys (*)
  f922b84... flatpak: Enable MPRIS (*)
  cb511a6... notificationspopup: Fix source not found warning

(*) This commit already existed in another branch; no separate mail sent