Fix getFormattedString to take only 2 params instead of 3.

suite/common/pref/pref-themes.js

@@ -53,7 +53,7 @@ function applySkin()
     var brandbundle = document.getElementById("bundle_brand");
     var dialogTitle = navbundle.getString("switchskinstitle");
     var brandName = brandbundle.getString("brandShortName");
-    var msg = navbundle.getFormattedString("switchskins", [brandName], 1);
+    var msg = navbundle.getFormattedString("switchskins", [brandName]);
     promptService.alert(window, dialogTitle, msg);
   }
 }