change the link of the Bug Report button (About)

[sonphantrung]

If your pull request is not translation or serverlist-related, read the list of requirements below and check each box:

• [x] I have read the contribution guidelines.
• [x] I have ensured that my code compiles, if applicable.
• [x] I have ensured that any new features in this PR function correctly in-game, if applicable.

As the repo now uses the GH Issues Template, the link should be changed (the one before no longer works).