Fix max score in combined xmodule tests

common/lib/xmodule/xmodule/tests/test_combined_open_ended.py

@@ -271,7 +271,7 @@ class CombinedOpenEndedModuleTest(unittest.TestCase):
         <option>The response is not a satisfactory answer to the question.  It either fails to address the question or does so in a limited way, with no evidence of higher-order thinking.</option>
         </category>
          </rubric></rubric>'''
-    max_score = 4
+    max_score = 3
 
     metadata = {'attempts': '10', 'max_score': max_score}