Add missing 'global' variable declaration

public/src/forum/category.js

@@ -1,5 +1,5 @@
 "use strict";
-/* global define, config, templates, app, ajaxify, socket, translator */
+/* global define, config, templates, app, utils, ajaxify, socket, translator */
 
 define(['composer', 'forum/pagination', 'share', 'navigator'], function(composer, pagination, share, navigator) {
 	var Category = {},
@@ -331,4 +331,4 @@ define(['composer', 'forum/pagination', 'share', 'navigator'], function(composer
 	};
 
 	return Category;
-});
+});