"fix" this warning by passing "%s" as the format string:

mod_authz_core.c: In function ‘authz_core_check_section’:
mod_authz_core.c:579: warning: format not a string literal and no format arguments


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@775460 13f79535-47bb-0310-9956-ffa450edef68