When the query string results in an invalid URL, PHP warnings are generated

There's a buggy spider that keeps crawling my site and requesting bogus URLs such as http://example.com/https:/example.com/user/register. Secure Pages calls parse_url() on the URLs, which, according to the PHP docs on that function, can cause PHP to issue a warning if the passed URL is invalid.

I've attached a patch that quells the warnings generated by this function.