Fix PR 15113, a core dump in cache_in_filter when

a redirect occurs. The code was passing a format string and
integer to apr_pstrcat. Changed to apr_psprintf. [Paul J. Reder]

PR: 15113


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@97971 13f79535-47bb-0310-9956-ffa450edef68