Backing out the AuthLDAPAllowDNAuth patch from r168016. Because of LDAP...

Backing out the AuthLDAPAllowDNAuth patch from r168016.  Because of LDAP filter issues this patch still can't guarantee unique results.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@168644 13f79535-47bb-0310-9956-ffa450edef68