Fix disappearing contact info

This errant reference to the global cache of conversations was causing
some contacts to get clobbered.

// FREEBIE

js/panel_controller.js

@@ -86,7 +86,7 @@
         var conversationId = message.get('conversationId');
         var conversation = ConversationController.get(conversationId);
         if (!conversation) {
-            conversation = conversations.create({id: conversationId});
+            conversation = ConversationController.create({id: conversationId});
             conversation.fetch();
         }