buffer: Ignore unknown events.

matrix/buffer.py

@@ -43,7 +43,8 @@ from nio import (
     RoomTopicEvent,
     MegolmEvent,
     Event,
-    OlmTrustError
+    OlmTrustError,
+    UnknownEvent
 )
 
 from . import globals as G
@@ -1389,6 +1390,9 @@ class RoomBuffer(object):
 
             self.undecrypted_events.append(event)
 
+        elif isinstance(event, UnknownEvent):
+            pass
+
         else:
             W.prnt(
                 "", "Unhandled event of type {}.".format(type(event).__name__)