fix: set rparticipant to None by default (#74)

Author: MDBox

livekit/room.py

@@ -314,6 +314,7 @@ def _on_room_event(self, event: proto_room.RoomEvent):
 
             data = bytearray(native_data)
             FfiHandle(owned_buffer_info.handle.id)
+            rparticipant = None
             if event.data_received.participant_sid:
                 rparticipant = self.participants[event.data_received.participant_sid]
             self.emit('data_received', data,