[gnome-photos] (9 commits) Non-fast-forward update to branch wip/rishi/gcc8

[Debarshi Ray <debarshir src gnome org>]

The branch 'wip/rishi/gcc8' 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:

  59be64c... data: Remove legacy screenshots
  0bcfac8... Silence -Wcast-function-type

Commits added to the branch:

  7ae8672... Revert "Revert "build: Update all AX_* macros from upstream (*)
  6624c0c... flatpak: Simplify TrackerSparqlConnection creation (*)
  baeecde... Update German translation (*)
  c648e20... data: Remove legacy screenshots (*)
  d2f4b3c... Update Greek translation (*)
  f22fdda... build: Update the Git submodule URL after GitLab migration (*)
  0e546cd... build: Unbreak by adding missing definition of AX_APPEND_LI (*)
  267e149... Silence -Wcast-function-type
  7ad7b01... build: Turn off -Wcast-function-type

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