aria2: fix homepage URL

[scribblemaniac]

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same formula update/change?
• Have you built your formula locally prior to submission with brew install <formula> (where <formula> is the name of the formula you're submitting)?
• Does your submission pass brew audit --strict --online <formula> (after doing brew install <formula>)?

Description

The project's homepage has moved. The old link redirects to the link I provided.

Edit: Running brew audit --strict --online aria2 results in the error:

  * C: 20: col 1: Extra empty line detected at method body beginning.

Since this was present before I modified the formula I did not change it. It probably belongs in a separate fix.

[apjanke]

Merged. Thank you for your contribution to Homebrew!

For future reference, audit fixes are minor and desirable, so you can go ahead and roll them in with any other change, like a version bump or this homepage update, as long as there's less than like a dozen lines changed.

[scribblemaniac]

Thanks, I'll keep that in mind!