[BUGFIX] Unresolved dependencies uses old flashmessage styling

The message when there are unresolved dependencies uses the old
flashmessage styling classes. Use the new classes.

Resolves: #62599
Releases: master
Change-Id: I3b48c6ae6ba19f771e81ce3de4bddefb2d509900
Reviewed-on: http://review.typo3.org/33690
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>