fix url

[hwulfmeyer]

Important: Do not tick a checkbox if you haven’t performed its action. Honesty is indispensable for a smooth review process.

In the following questions <cask> is the token of the cask you're submitting.

After making all changes to a cask, verify:

• [x] The submission is for a stable version or documented exception.
• [ ] brew audit --cask --online <cask> is error-free.
• [ ] brew style --fix <cask> reports no offenses.