Remove unnecessary assignment

common/lib/xmodule/xmodule/open_ended_grading_classes/openendedchild.py

@@ -101,7 +101,6 @@ class OpenEndedChild(object):
         self.close_date = static_data['close_date']
         self.s3_interface = static_data['s3_interface']
         self.skip_basic_checks = static_data['skip_basic_checks']
-        self.system = system
 
         # Used for progress / grading.  Currently get credit just for
         # completion (doesn't matter if you self-assessed correct/incorrect).