Hack out sending AS events for bridged users

Author: bradtgmurray

synapse/appservice/__init__.py

@@ -150,6 +150,11 @@ async def _matches_user(
         if not event:
             return False
 
+        # Beeper Hack
+        # Don't bother sending events for bridged users, the bridge presumably already knows this happened.
+        if event.sender.startswith("@_"):
+            return False
+
         if self.is_interested_in_user(event.sender):
             return True
         # also check m.room.member state key