fix: skip mobile menu setup if Pulling not found

lib/persona.js

@@ -143,6 +143,10 @@ $(document).ready(function() {
 
 
 		require(['pulling', 'storage'], function (Pulling, Storage) {
+			if (!Pulling) {
+				return;
+			}
+
 			// initialization
 
 			var chatMenuVisible = !config.disableChat && app.user && parseInt(app.user.uid, 10);