Use consumeErrors=True on all DeferredLists.

This is so that the DeferredLists actually consume the error instead of
propogating down the non-existent errback chain. This should reduce the
number of unhandled errors we are seeing.

synapse/federation/federation_server.py

@@ -124,7 +124,7 @@ class FederationServer(FederationBase):
                         edu.content
                     )
 
-            results = yield defer.DeferredList(dl)
+            results = yield defer.DeferredList(dl, consumeErrors=True)
 
         ret = []
         for r in results:

synapse/federation/transaction_queue.py

@@ -98,7 +98,7 @@ class TransactionQueue(object):
 
             deferreds.append(deferred)
 
-        yield defer.DeferredList(deferreds)
+        yield defer.DeferredList(deferreds, consumeErrors=True)
 
     # NO inlineCallbacks
     def enqueue_edu(self, edu):