Fix comparison for overwrites when checking if a channel is synced

discord/abc.py

@@ -440,7 +440,7 @@ class GuildChannel:
         .. versionadded:: 1.3
         """
         category = self.guild.get_channel(self.category_id)
-        return bool(category and category._overwrites == self._overwrites)
+        return bool(category and category.overwrites == self.overwrites)
 
     def permissions_for(self, member):
         """Handles permission resolution for the current :class:`~discord.Member`.