fixing up moderator listing

src/categories.js

@@ -40,6 +40,8 @@ var	RDB = require('./redis.js'),
 
 	Categories.getModerators = function(cid, callback) {
 		RDB.smembers('cid:' + cid + ':moderators', function(err, mods) {
+			if (mods.length === 0) return callback([]);
+
 			user.getMultipleUserFields(mods, ['username'], function(details) {
 				var moderators = [];
 				for(u in details) {

src/topics.js

@@ -133,6 +133,7 @@ var	RDB = require('./redis.js'),
 							'category_id': category_id || 0,
 							'topics': topics,
 							'active_users': active_users,
+							'moderator_block_class': moderators.length > 0 ? '' : 'none',
 							'moderators': moderators
 						});
 					}