[BUGFIX] Avoid PHP undefined array access in BrowseLinksController

Resolves: #103360
Releases: main, 12.4
Change-Id: I6331f4ed9d061a06962d0e70affa43bc239a78a9
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83401


Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Garvin Hicking <gh@faktor-e.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Jasmina Ließmann <minapokhalo+typo3@gmail.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Garvin Hicking <gh@faktor-e.de>
Reviewed-by: Jasmina Ließmann <minapokhalo+typo3@gmail.com>