[BUGFIX] Check parsed option in EmailFinisher

To prevent PHP warnings for passing invalid
arguments to "foreach", the parsed option
is now checked to be a non empty array.

Resolves: #97463
Releases: main, 11.5
Change-Id: Id66a448886baf99ad0b2aaef1d3291ac0aae7dff
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/74396


Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>