[BUGFIX] Prevent non-numeric value warning in ErrorHandler.php

Prevents a non-numeric value warning in ErrorHandler.php by
casting the value given to the parameter of the constructor to an int.

Resolves: #91930
Releases: master, 10.4, 9.5
Change-Id: I000596ee0bdf8599a2eadea5216286971a94c806
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/65182


Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>