Another string -> bytes fix when parsing a FeedbackReport

feedbackloop/arf.py

@@ -75,8 +75,8 @@ class ARFMessage(object):
         """ Returns the message/feedback-report part as a FeedbackReport """
         part = self._get_part('feedback-report')
         if part:
-            return Parser(FeedbackReport).parsestr(
-                part.get_payload()[0].as_string())
+            return BytesParser(FeedbackReport).parsebytes(
+                part.get_payload()[0].as_bytes())
 
     def get_original_message_headers(self):
         """ Returns headers from the orginal message """