Possbile bug in dingtalk webhook

[zaaksam]

• Gitea version (or commit ref):
  1.4.0+rc1-1-gf61ef28 and reproduce on 2cb4649

• Can you reproduce the bug at https://try.gitea.io:
  https://try.gitea.io/ystech/demo

Description

I add a dingtalk webhook, it works fine on "Just the push event" and "I need everything".
But when I choose the "Let me choose what I need" option, it doesn't work.

I create a "Pull Request" and then open and close it repeatedly, I didn't receive any notice in the dingtalk. "Test Delivery" had the same problem.

Screenshots

Recent Deliveries, but I didn't receive.