Skip None action types when iterating.

discord/iterators.py

@@ -477,4 +477,8 @@ class AuditLogIterator(_AsyncIterator):
                 self._users[u.id] = u
 
             for element in data:
+                # TODO: remove this if statement later
+                if element['action_type'] is None:
+                    continue
+
                 yield from self.entries.put(AuditLogEntry(data=element, users=self._users, guild=self.guild))