[gthumb] Created tag 3.10.4

[Paolo Bacchilega <paobac src gnome org>]

The unsigned tag '3.10.4' was created.

Tagger: Paolo Bacchilega <paobac src gnome org>
Date: 1629654511 +0200

    version 3.10.4

Changes since the last tag '3.10.3':

Asier Sarasua Garmendia (1):
      Update Basque translation

Bruce Schultz (1):
      meson: Install the gThumb import desktop file

Daniel Șerbănescu (2):
      Update Romanian translation
      Update Romanian translation

Paolo Bacchilega (4):
      contact sheet: fixed themes list always empty
      file chooser: correctly get the filename extension
      thumbnailer: try with the system thumbnailer if the image is null
      updated for version 3.10.4