gitless: fix patch url

[gromgit]

In support of Homebrew/brew#8075

• Have you followed the guidelines for contributing?
• Have you checked that there aren't other open pull requests for the same formula update/change?
• Have you built your formula locally with brew install --build-from-source <formula>, where <formula> is the name of the formula you're submitting?
• Is your test running fine brew test <formula>, where <formula> is the name of the formula you're submitting?
• Does your build pass brew audit --strict <formula> (after doing brew install <formula>)?

---

[gromgit]

Error: 1 problem in 1 formula detected
gitless:
  * v0.8.8 is a GitHub prerelease

All gitless releases are prereleases. Disable?

[jonchang]

We have a GITHUB_PRERELEASE_ALLOWLIST somewhere that this could be added to.

[dtrodrigues]

https://github.com/Homebrew/brew/blob/master/Library/Homebrew/dev-cmd/audit.rb#L635