[BUGFIX] Fix typo in PageRenderer comments

Fixes: #53009
Releases: 6.2
Change-Id: I95f95f568f3d9745aaed8e4c7bb8ec10957cf698
Reviewed-on: https://review.typo3.org/24928
Reviewed-by: Mattias Nilsson
Tested-by: Mattias Nilsson
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters