[BUGFIX] Use mod.linkvalidator settings in scheduler

Since mod.linkvalidator is used in all other places in the linkvalidator
as TSConfig key it is now also used in the scheduler to override existing
TSConfig.

To maintain backward compatibility the old mod.tx_linkvalidator setting
will be respected and a deprecation warning will be logged.

Resolves: #51360
Releases: master
Change-Id: I6e6692d2ff6543f1154e4d64feb52efc5cdfcf83
Reviewed-on: http://review.typo3.org/26513


Reviewed-by: Benjamin Mack <benni@typo3.org>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Benjamin Mack <benni@typo3.org>
Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>