Fix a couple of bugs in presence handler related to pushing updatesto the correct user. Fix presence tests.

synapse/federation/replication.py

@@ -543,6 +543,8 @@ class _TransactionQueue(object):
         def eb(failure):
             if not deferred.called:
                 deferred.errback(failure)
+            else:
+                logger.exception("Failed to send edu", failure)
         self._attempt_new_transaction(destination).addErrback(eb)
 
         return deferred