[BUGFIX] Always use uc_default after first install

If the Install Tool sets the start module on first login to allow the
installation of a distribution the uc_default settings must still be
applied. A special temporary setting by the Install Tool makes it easy
to detect this situation.

Resolves: #66432
Releases: master
Change-Id: Icb779860c54fd53af6c38437ab2dedad846a9fbc
Reviewed-on: http://review.typo3.org/38834


Reviewed-by: Andreas Fernandez <andreas.fernandez@aspedia.de>
Tested-by: Andreas Fernandez <andreas.fernandez@aspedia.de>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>