[BUGFIX] Restore field descriptions in Install Tool

In the Install Tool All Configuration part all field descriptions
are missing. This patch removes the additional newline characters
which caused the comments used to render the descriptions being
moved away from their fields.

Change-Id: I0c6db43b6940494405eb794a28a684d1894b046e
Fixes: #40939
Releases: 6.0
Reviewed-on: http://review.typo3.org/14607
Reviewed-by: Markus Klein
Tested-by: Markus Klein
Reviewed-by: Helmut Hummel
Tested-by: Helmut Hummel