Merge r607282 from trunk:

* Ensure refresh parameter is numeric to prevent a possible XSS attack caused
  by redirecting to other URLs. Reported by SecurityReason.

Submitted by: Mark Cox, Joe Orton
Reviewed by: rpluem, wrowe, jorton


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@607408 13f79535-47bb-0310-9956-ffa450edef68