Links for commit hashes ending in comma are not rendered

[nuno-silva]

• Gitea version (or commit ref): 1.14.0+dev-499-g7576e37a6
• Git version: NA
• Operating system: NA
• Database: NA
• Can you reproduce the bug at https://try.gitea.io:
  • Yes https://try.gitea.io/nuno-silva/test/issues/8
  • No

Description

When leaving an issue comment containing valid commit hashes, those are not recognised if they are followed by a comma (,).
A workaround is to leave a space between the hash and the comma, but you need to remember to do it when writing the comment or go back and edit it after noticing the commit link was not rendered.
Dots are accepted though. See the screenshot for reference.

Unless there was a specific reason for not accepting commas, this is an easy fix.
I will prepare a pull request in a bit.

Screenshots