[TASK] Make RootlineUtilityTest.php notice free

Releases: master
Resolves: #85093
Change-Id: Ib5c8fbf7d4a69d05b0fb370440fba0bc755e5854
Reviewed-on: https://review.typo3.org/57064


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>