[CLEANUP] Remove some obsolete PHP version checks

With hard requirement of PHP 5.5 and above a couple of
php version checks are obsolete and can be removed.

Resolves: #63461
Releases: master
Change-Id: Ib1dd7540fa6d3818809bb4d760bc730de23a7da2
Reviewed-on: http://review.typo3.org/34824
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>