Fix a XSS vulnerability in the review request page.
Fix a XSS vulnerability in the review request page.

This vulnerability allowed an attacker to craft a URL that would execute
JavaScript on a user's behalf. This was found and fixed by Anthony
Steinhauser.

Reviewed at https://reviews.reviewboard.org/r/8863/

reviewboard/reviewboard,chipx86/reviewboard,reviewboard/reviewboard,chipx86/reviewboard,brennie/reviewboard,brennie/reviewboard,chipx86/reviewboard,chipx86/reviewboard,brennie/reviewboard,reviewboard/reviewboard,brennie/reviewboard,reviewboard/reviewboard