Added a support comment, and updated spacing

As discussed in #1597.
@markelog Here's the Git commit which fixed 8138. https://github.com/jquery/jquery/commit/e3cc440934fcb03bfeb10fb6281615409ad6f483/

Previous to this, on line 364, `document.location` was being used. The following line referenced the `protocol` property of `document.location`.

Therefore, this commit fixed the issue I brought up. Before that commit, I think it was a concern, since `document.location` was being referenced. Please correct me if I'm wrong, though.

If you have a test that can reproduce another issue though, it totally makes sense to include that test as well.