issue was not closed via commit but added a reference event

Summary

(Summarize the bug encountered concisely)
I want to close issue via commit message, but fail.
Meanwhile, it was just added a commit reference whose massage contain the close statement.

Steps to reproduce

(How one can reproduce the issue - this is very important)

1. make a commit with multi-line commit message

2. close the issue number in the message's footer, like this:

    test(close issue): issue #xx should be closed
    
    more message about the commit
    
    close #xx

3. just push the commit to the repository on gitlab.com

What is the current bug behavior?

(What actually happens)

1. the issue closed by commit remains open
2. an event massage about "sombody mentioned in commit" appear in the issue

What is the expected correct behavior?

(What you should see instead)
after refresh the web page, the issue should be closed

Relevant logs and/or screenshots

(Paste any relevant logs - please use code blocks (```) to format console output, logs, and code as it's very hard to read otherwise.)
issue with the bug: https://gitlab.com/sysu-gitlab/latex-group/thesis/issues/8
Related commit: https://gitlab.com/sysu-gitlab/latex-group/thesis/commit/c6f4ab9bd006cf7ae1a73d929147496caea952d2

Output of checks

(If you are reporting a bug on GitLab.com, write: This bug happens on GitLab.com)
This bug happens on GitLab.com