[TASK] Use real boolean value for trimExplode third param

Make use of boolean value TRUE as third parameter in
trimExplode function.

Change-Id: Ied33efac6cddfc2e2798435fe9b1ef748c11905b
Resolves: #50402
Releases: 6.2
Reviewed-on: https://review.typo3.org/22542
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind