[CLEANUP] #4400 Use strict comparisons

Change-Id: I004ece522ec41687076d100b77e083803e84b68e
Reviewed-on: http://review.typo3.org/35056
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>