Jump to last post in "Best of" mode fix

http://meta.discourse.org/t/jump-to-last-post-does-not-work-in-best-of-mode/7626/

app/assets/javascripts/discourse/controllers/topic_controller.js

@@ -135,7 +135,7 @@ Discourse.TopicController = Discourse.ObjectController.extend(Discourse.Selected
 
   jumpBottom: function() {
     if (this.get('bestOf')) {
-      Discourse.TopicView.scrollTo(this.get('id'), this.get('posts').last().get('post_number'));
+      Discourse.TopicView.scrollTo(this.get('id'), _.last(this.get('posts')).get('post_number'));
     } else {
       Discourse.URL.routeTo(this.get('lastPostUrl'));
     }