gdk3 test: suppress a warning
gdk3 test: suppress a warning

    Gdk-CRITICAL **:gdk_pixbuf_get_from_surface: assertion 'width > 0 && height > 0' failed

kitachro/ruby-gnome2,kitachro/ruby-gnome2,kitachro/ruby-gnome2,kitachro/ruby-gnome2,kitachro/ruby-gnome2