[BUGFIX] Don't disable redirect after logout with showLogoutFormAfterLogin=1

This patch fixes a regression where showLogoutFormAfterLogin was added
as a condition to disable redirects in fe_login at all when it should
only disable redirects after login.

Change-Id: Ide5c17f202618c9c0696bc777473a7be1b089276
Resolves: #73144
Releases: master, 7.6
Reviewed-on: https://review.typo3.org/48025


Reviewed-by: Frank Naegler <frank.naegler@typo3.org>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Zbigniew Jacko <z.jacko@macopedia.pl>
Tested-by: Zbigniew Jacko <z.jacko@macopedia.pl>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>