Backport: Use HTML 2.0 <hr> for error pages. PR 30732

PR:
Obtained from:
Submitted by:	nd
Reviewed by:	nd, jorton, trawick, jerenkrantz


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@105271 13f79535-47bb-0310-9956-ffa450edef68