[FIX] In templatePath TS constants aren't replaced

Change-Id: Ia5688a3e649aa24d805a0c67a85059afcbcc7b5c
Resolves: #51076
Releases: 2.3, 3.0
Reviewed-on: http://review.typo3.org/31751
Reviewed-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>
Tested-by: Stefan Neufeind <typo3.neufeind@speedpartner.de>