[BUGFIX] Add check for salted default admin password

Check for default password of admin account no longer
works in status reports module.

Change-Id: Ibefcadb60afb2d22490fc1219559d8651d256c8a
Fixes: #31397
Releases: 4.6, 4.7
Reviewed-on: http://review.typo3.org/6392
Reviewed-by: Markus Klein
Tested-by: Philipp Gampe
Reviewed-by: Philipp Gampe
Reviewed-by: Francois Suter
Tested-by: Francois Suter