Removed vetigial argument and properly aligned post_store

web/react/stores/post_store.jsx

@@ -69,8 +69,8 @@ var PostStore = assign({}, EventEmitter.prototype, {
         this.removeListener(SELECTED_POST_CHANGE_EVENT, callback);
     },
 
-  emitMentionDataChange: function(id, mentionText, excludeList) {
-    this.emit(MENTION_DATA_CHANGE_EVENT, id, mentionText, excludeList);
+    emitMentionDataChange: function(id, mentionText) {
+        this.emit(MENTION_DATA_CHANGE_EVENT, id, mentionText);
     },
 
     addMentionDataChangeListener: function(callback) {