[BUGFIX] Avoid undefined array key frequencyOptions

Resolves: #98915
Releases: 11.5
Change-Id: I6a9236f08d8446f465d6bccb72c6f5bad4c5b473
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76256


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>