[gtk] (2 commits) Non-fast-forward update to branch wip/otte/for-main

[Benjamin Otte <otte src gnome org>]

The branch 'wip/otte/for-main' 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:

  2e9e841... glrenderer: Don't return NULL form render_texture()
  eb5d085... flattenlistmodel: Fix indentation
  3754ddd... listview: Fix return_if_fail()s

Commits added to the branch:

  6863f9f... glrenderer: Don't return NULL form render_texture()
  d58c63e... flattenlistmodel: Fix indentation