[BUGFIX] Fix message for install tool warning

Fix incorrect message for install tool login attempt warning.

Resolves: #54531
Releases: 6.2, 6.1
Change-Id: I40f34b85ffc554187baf1f2601c578cbaafc5718
Reviewed-on: https://review.typo3.org/26529
Reviewed-by: Markus Klein
Tested-by: Markus Klein