WikimediaUI theme: Fix border on narrow bottom toolbars
WikimediaUI theme: Fix border on narrow bottom toolbars

Fixing narrow bottom toolbars' overflow border.

Change-Id: I58ac419d93a98aafe69e2de99e841a1c41039221

wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui,wikimedia/oojs-ui