Remove invalid await in replication code (#400)

changelog.d/400.bugfix

@@ -0,0 +1 @@
+Fix an issue which could cause new local associations to be replicated multiple times to peers.

sydent/replication/pusher.py

@@ -112,7 +112,7 @@ class Pusher:
             )
             result = await p.pushUpdates(assocs)
 
-            await self.peerStore.setLastSentVersionAndPokeSucceeded(
+            self.peerStore.setLastSentVersionAndPokeSucceeded(
                 p.servername, latest_assoc_id, time_msec()
             )