[libmediaart] (2 commits) Non-fast-forward update to branch sam/valid-utf8

[Sam Thursfield <sthursfield src gnome org>]

The branch 'sam/valid-utf8' 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:

  0544775... Mandate that inputs are valid UTF8

Commits added to the branch:

  517a22d... Rationalize NULL/empty string handling in media_art_strip_i (*)
  d4551d9... Mandate that inputs are valid UTF8 (*)

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