[FOLLOWUP] This is FormEngine

Correct clearing for --linebreaks-- within palettes.

Releases: master
Resolves: #64762
Change-Id: I9a7473e073cb9d563da3a645e1813fbff7dc1102
Reviewed-on: http://review.typo3.org/36638


Reviewed-by: Frederic Gaus <gaus@flagbit.de>
Tested-by: Frederic Gaus <gaus@flagbit.de>
Reviewed-by: Steffen Müller <typo3@t3node.com>
Tested-by: Steffen Müller <typo3@t3node.com>