[BUGFIX] Add case insensitive flag to trustedHostsPattern

Releases: master, 6.2, 4.5
Resolves: #59186
Change-Id: Iaa973faf5b3f287320fb187c3db2d8e30a486735
Reviewed-on: http://review.typo3.org/35444
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>