Renaming task causes duplicated threads

[Norbiros]

https://discord.com/channels/1306688207261274212/1457092588120178690/1457092588120178690
https://discord.com/channels/1306688207261274212/1457043412250529938/1457043412250529938

[Sanielia]

so problem was that after post creation, new post id wasn't saved in post_id db, so if nothing changed between item creation and title change, then from bot perspective post didn't exist yet, resolved in recent commit