Fix message.payload_type

coapthon/serializer.py

@@ -113,10 +113,13 @@ class Serializer(object):
                         raise AttributeError("Packet length %s, pos %s" % (length_packet, pos))
                     message.payload = ""
                     payload = values[pos:]
+                    try:
                         if message.payload_type == defines.Content_types["application/octet-stream"]:
                             message.payload = payload
                         else:
                             message.payload = payload.decode("utf-8")
+                    except AttributeError:
+                        message.payload = payload.decode("utf-8")
                     pos += len(payload)
 
             return message