Stop calling updateInbox all the time

Now that the inbox collection keeps itself in sync, we don't have the
data duplication that was forcing us to reload constantly.

// FREEBIE

js/panel_controller.js

@@ -50,7 +50,6 @@
             });
         } else {
             openConversation(conversation);
-            ConversationController.updateInbox();
         }
     };