### Description In a new repository * Create `.gitea/default_merge_message/SQUASH_TEMPLATE.md` with contents for example: ``` ${PullRequestTitle} ``` * Create an issue * Create a pull request with title `Fix #1` * 500 error when going to the pull request page It's crashing at `services/pull/merge.go:101` while constructing `$ClosingIssues` for the template. Can be seen here: https://try.gitea.io/brechtvl/test/pulls/2 ### Gitea Version 5ae07d4 (main) ### Can you reproduce the bug on the Gitea demo site? Yes ### Log Gist _No response_ ### Screenshots _No response_ ### Git Version _No response_ ### Operating System _No response_ ### How are you running Gitea? Both self built and try.gitea.io. ### Database None