Update peer grading comment

common/lib/xmodule/xmodule/peer_grading_module.py

@@ -93,7 +93,7 @@ class PeerGradingModule(PeerGradingFields, XModule):
         if not self.ajax_url.endswith("/"):
             self.ajax_url = self.ajax_url + "/"
 
-        #This could result in an exception, but not wrapping in a try catch block so it moves up the stack
+        #StringyInteger could return None, so keep this check.
         if not isinstance(self.max_grade, int):
             raise TypeError("max_grade needs to be an integer.")