Fix another long-standing bug in sub_req_lookup_file where it would

happily skip past access checks on subdirectories looked up with
relative paths.  (It's used by mod_dir, mod_negotiation,
and mod_include.)


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@78910 13f79535-47bb-0310-9956-ffa450edef68