[BUGFIX] Don't add TypoScript twice to defaultContentRendering

Calling the addTypoScript() method with last parameter set to
'defaultContentRendering' must not add the TypoScript twice.

Resolves: #67116
Releases: master, 6.2
Change-Id: I3161c62ac0ab25369fabc3f8163e5d92356aa0ca
Reviewed-on: http://review.typo3.org/39680


Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Helmut Hummel <helmut.hummel@typo3.org>
Tested-by: Helmut Hummel <helmut.hummel@typo3.org>
Reviewed-by: Stephan Großberndt <stephan@grossberndt.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>