Resolve "Changing feedback that a reviewer worken on is forbidden after set to final"

Closes #168 (closed)

core/serializers/feedback.py

@@ -121,7 +121,7 @@ class FeedbackSerializer(DynamicFieldsModelSerializer):
         submission = validated_data.pop('of_submission')
         feedback_lines = validated_data.pop('feedback_lines', [])
         labels = validated_data.pop('labels', [])
-        user = UserAccount.objects.get(username=str(self.context['request'].user))
+        user = self.context['request'].user
         feedback = Feedback.objects.create(of_submission=submission,
                                            **validated_data)
         if user.role == UserAccount.REVIEWER: