Don't show tipsy for an unknown language

Includes an update from upstream.

Bug: 46841
Change-Id: I5a221037af72319f2220bb54230a9549046b6024

resources/js/ext.uls.interface.js

@@ -147,7 +147,7 @@
 			return true;
 		}
 
-		if ( previousLang === currentLang ) {
+		if ( previousLang === currentLang || !$.uls.data.languages[previousLang] ) {
 			// Do not show tooltip.
 			return true;
 		}