gl: cope with positive stride in put_image()
gl: cope with positive stride in put_image()

Keeping the warning, because I don't think this should happen anyway.

Fantu/spice-common,Fantu/spice-common,elmarco/spice-common,fgouget/spice-common,Fantu/spice-common,fgouget/spice-common,elmarco/spice-common,SPICE/spice-common,SPICE/spice-common,SPICE/spice-common,freedesktop-unofficial-mirror/spice__spice-common,freedesktop-unofficial-mirror/spice__spice-common,fgouget/spice-common,Fantu/spice-common,freedesktop-unofficial-mirror/spice__spice-common,elmarco/spice-common,freedesktop-unofficial-mirror/spice__spice-common,elmarco/spice-common,fgouget/spice-common