[BUGFIX] Proper handling of allowedTables='*' in FormEngine

The output of FormEngine needs to be changed if all tables are
allowed for a relation.

Change-Id: Ib83c39120a3c20d99982e80b9a40b9f0fb7a4a72
Resolves: #64849
Releases: master
Reviewed-on: http://review.typo3.org/36650


Reviewed-by: Göran Bodenschatz <coding@46halbe.de>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>
Reviewed-by: Frederic Gaus <gaus@flagbit.de>
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Reviewed-by: Mathias Schreiber <mathias.schreiber@wmdb.de>
Tested-by: Mathias Schreiber <mathias.schreiber@wmdb.de>