Fix unwanted AttributeError in messagetypes

src/messagetypes/message.py

@@ -23,7 +23,7 @@ class Message(MsgBase):
             self.data["subject"] = data["subject"]
             self.data["body"] = data["body"]
         except KeyError as e:
-            logger.error("Missing key %s", e.name)
+            logger.error("Missing key %s", e)
         return self.data
 
     def process(self):

src/tests/core.py

@@ -70,6 +70,14 @@ class TestCore(unittest.TestCase):
         self.assertEqual(msg_data['subject'], obj3e.subject)
         self.assertEqual(msg_data['body'], obj3e.body)
 
+        try:
+            MsgEncode({'body': 'A msg with no subject'}, 3)
+        except Exception as e:
+            self.fail(
+                'Exception %s whyle trying to encode message'
+                ' with no subject!' % e
+            )
+
     def _wipe_knownnodes(self):
         with knownnodes.knownNodesLock:
             knownnodes.knownNodes = {stream: {} for stream in range(1, 4)}