Update app.py

app.py

@@ -83,7 +83,7 @@ async def on_message(message):
             print("3")
             slack_thread_ts = thread_mapping[discord_thread_id]
             # post to slack only if thread already exists
-            post_to_slack_forum_version(SLACK_CHANNEL_ID, message.content, thread_ts=slack_thread_ts)
+            post_to_slack_forum_version(SLACK_CHANNEL_ID, message.content, thread.owner, thread_ts=slack_thread_ts)
 
 
 @bot.event