xqueue_callback uses 'xqueue_body' tag rather than 'response' tag for main message

common/lib/xmodule/xmodule/capa_module.py

@@ -339,7 +339,7 @@ class CapaModule(XModule):
         No ajax return is needed. Return empty dict.
         """
         queuekey = get['queuekey']
-        score_msg = get['response']
+        score_msg = get['xqueue_body']
         self.lcp.update_score(score_msg, queuekey)
 
         return dict()  # No AJAX return is needed