[BUGFIX] Make filter respect hidden directories

Make the filename filter respect files in hidden directories,
so that files inside those are not indexed by default.

Resolves: #60649
Releases: master, 6.2
Change-Id: Ia0306cb8996964c4998d9d69b526c3d6a8da2ace
Reviewed-on: http://review.typo3.org/31890
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>