[BUGFIX] Ensure PHP 5.2 compatibility in php-openid

The backport #62357 introduced a regression with PHP 5.2,
which still is officially supported by TYPO3 CMS 4.5

Adapt the code to be PHP 5.2 compatible

Resolves: #62391
Releases: 4.5
Change-Id: I72895592e10d963f2777c4659cc1f0a10e69a1c1
Reviewed-on: http://review.typo3.org/33737
Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>