[TASK] Clarify install tool no-password-set message

Change-Id: I4a66d5975921fdff64af33e4c745d5ab05ff0f70
Releases: master, 6.2
Resolves: #68324
Reviewed-on: http://review.typo3.org/41645


Reviewed-by: Loek Hilgersom <loek@netcoop.nl>
Tested-by: Loek Hilgersom <loek@netcoop.nl>
Reviewed-by: Andreas Wolf <andreas.wolf@typo3.org>
Tested-by: Andreas Wolf <andreas.wolf@typo3.org>