[TASK] Described default value of lockingmode is wrong

Install Tool says that default value is "disable" but
actually it is "simple".

Change-Id: Id3d5f1211c6cf38e1717bc01068e9464c4a0ba86
Resolves: #25038
Releases: 6.1
Reviewed-on: https://review.typo3.org/20132
Reviewed-by: Sascha Egerer
Tested-by: Sascha Egerer
Reviewed-by: Wouter Wolters
Tested-by: Wouter Wolters
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring