by superwin, the visual is being obtained by calling gdk_visual_get_system().
This was causing match errors when gdk_rgb picked a visual having a depth that
was different from the server default visual. r=pavlov, fixes bugs 20153 and
19263.
git-svn-id: svn://10.0.0.236/trunk@54878 18797224-902f-48f8-a5cc-f745e15eee43