[BUGFIX] EXT:filelist Fixed exception when the base path does not exists

Resolves: #79785
Releases: master, 8.7
Change-Id: I50cf03273747b1fa32a1f8e4aac993a3fbc7b7f0
Reviewed-on: https://review.typo3.org/55476


Tested-by: TYPO3com <no-reply@typo3.com>
Tested-by: Jan Stockfisch <jan.stockfisch@googlemail.com>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Timo Pfeffer <pfeffer.timo+typo3@gmail.com>
Reviewed-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Tested-by: Mathias Schreiber <mathias.schreiber@typo3.com>
Reviewed-by: Joerg Boesche <typo3@joergboesche.de>
Reviewed-by: Tobi Kretschmann <tobi@tobishome.de>
Tested-by: Tobi Kretschmann <tobi@tobishome.de>
Reviewed-by: Susanne Moog <susanne.moog@typo3.org>
Tested-by: Susanne Moog <susanne.moog@typo3.org>