Mail - closing pull request generates same message as new pull request

[vakabus]

• Gitea version (or commit ref): c5ec66a
• Can you reproduce the bug at https://try.gitea.io:
  • Yes (provide example URL)
  • No - I haven't received any emails from there
  • Not relevant

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Description

When closing a pull request without a merge, an email notification is sent out with the same content as the message about new pull request. Nothing indicates, that the pull request has been closed. Expected behaviour would be, that the email would at least contain "pull request closed".

[vakabus]

Pretty much same issue with different action - when reopening PR, the first comment is sent out again. Expected would be a simple message just about reopening it.

[guillep2k]

Should be fixed by #8329 by improving the subject line. I think it's good to maintain the original issue content as the body of the mail if the subject is clear about what has been done.