Handle missing media type field

mautrix_instagram/portal.py

@@ -1074,6 +1074,8 @@ class Portal(DBPortal, BasePortal):
             raise ValueError("Attachment not available: unsupported media type")
         elif isinstance(media_data, ExpiredMediaItem):
             self.log.debug(f"Expired media in item {item}")
+            if not media_data.media_type:
+                raise ValueError("Sent a media message")
             raise ValueError(f"Sent {media_data.media_type.articled_alt_human_name}")
         return method, media_data