#47368 unpredefined languages entry should appears in accepted languages list once selected

ra=ftang
forgot a code path in previous checkin.

xpfe/components/prefwindow/resources/content/pref-languages.js

@@ -320,6 +320,8 @@ function AddAvailableLanguage()
     Languageid	    = otherField.value;
     Languageid      = Languageid.toLowerCase();
 	  Languagename		= GetLanguageTitle(Languageid);
+    if (!Languagename)
+       Languagename = '[' + Languageid + ']';
 	  already_active	= false;	
   
     if (!LangAlreadyActive(Languageid)) {