[BUGFIX] Security status for saltedpasswords broken

Due to the new flashmessage styling the checks done for
saltedpasswords don't work anymore. Change the checks to the
new class names.

Resolves: #62598
Releases: master
Change-Id: Iea269f1d138e58cd551fa5575f3b03455a48d930
Reviewed-on: http://review.typo3.org/33689
Reviewed-by: Frank Nägler <typo3@naegler.net>
Tested-by: Frank Nägler <typo3@naegler.net>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>