Fix running afterCreateChannel callbacks

The only place where afterCreateChannel callback is added is 
https://github.com/RocketChat/Rocket.Chat/blob/develop/packages/rocketchat-piwik/client/trackEvents.js#L29
where the callback has the created room as the only argument.

packages/rocketchat-lib/server/functions/createRoom.js

@@ -86,7 +86,7 @@ RocketChat.createRoom = function(type, name, owner, members, readOnly, extraData
 
 	if (type === 'c') {
 		Meteor.defer(() => {
-			RocketChat.callbacks.run('afterCreateChannel', owner, room);
+			RocketChat.callbacks.run('afterCreateChannel', room);
 		});
 	}