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

Change-Id: Ib69a4a2a08b1edbc0f40beac00f7f68075b479a1
Reviewed-on: https://gerrit.libreoffice.org/66967
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>