[BUGFIX] Fix some PHP Notices thrown when rendering page module

Resolves: #82921
Releases: master, 8.7
Change-Id: Id26239e65321aa3653de849932a0be7e626bd653
Reviewed-on: https://review.typo3.org/54558


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Frans Saris <franssaris@gmail.com>
Tested-by: Frans Saris <franssaris@gmail.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>