Fix events.MessageDeleted setting readonly properties

telethon/events/messagedeleted.py

@@ -30,12 +30,5 @@ class MessageDeleted(EventBuilder):
             super().__init__(
                 chat_peer=peer, msg_id=(deleted_ids or [0])[0]
             )
-            if peer is None:
-                # If it's not a channel ID, then it was private/small group.
-                # We can't know which one was exactly unless we logged all
-                # messages, but we can indicate that it was maybe either of
-                # both by setting them both to True.
-                self.is_private = self.is_group = True
-
             self.deleted_id = None if not deleted_ids else deleted_ids[0]
             self.deleted_ids = deleted_ids