Update htcacheclean defines to match mod_disk_cache.c, Andreas is working on

mod_disk_cache.h, an all-round better solution, but for now just fix the
bug.



git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@239381 13f79535-47bb-0310-9956-ffa450edef68