[TASK] Update IDNA-class to 0.8.1

Change-Id: I1aaf487c43adc7e36fa98aaf972094fa13d1e764
Resolves: #53902
Releases: 6.2
Reviewed-on: https://review.typo3.org/25667
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer