[BUGFIX] EXT:form - Wrong Checkbox and Radiobutton handling

Resolves: #70095
Releases: master
Change-Id: I55ba94d13a8aeb02858675d2924f1d8a75cea698
Reviewed-on: http://review.typo3.org/43543


Reviewed-by: Frans Saris <franssaris@gmail.com>
Tested-by: Frans Saris <franssaris@gmail.com>
Reviewed-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Tested-by: Bjoern Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Oliver Hader <oliver.hader@typo3.org>
Tested-by: Oliver Hader <oliver.hader@typo3.org>