[BUGFIX] Check default salting method first

Prioritise default salting hashing method when determining
the salting hashing method of a given salted hash.

Fixes rare cases when the method "isValidSaltedPW()" returns TRUE
for similar salting implementations.

Resolves: #54833
Releases: 6.2
Change-Id: I58eb214f171de9f285a7818edebd925eb8164888
Reviewed-on: https://review.typo3.org/26692
Reviewed-by: Anja Leichsenring
Tested-by: Anja Leichsenring
Reviewed-by: Jigal van Hemert
Reviewed-by: Stefan Neufeind
Tested-by: Stefan Neufeind