Since it is now possible to use C++14, it's time to replace
the temporary solution with the standard one

Change-Id: Iad5a422bc5a7da43d905edc91d1c46793332ec5e
Reviewed-on: https://gerrit.libreoffice.org/66545
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>