Bugfix for PEAR bug #19760

Bugfix by http://pear.php.net/user/joris, see http://pear.php.net/bugs/bug.php?id=19760&edit=12&patch=HTML_QuickForm_Rule_Required&revision=1356440485
Merge pull request #1 from powtac/patch-1

Bugfix for PEAR bug #19760