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

Change-Id: I8bee1344f7df82536f31bc5e4ec4fd379cac1d04
Reviewed-on: https://gerrit.libreoffice.org/66704
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>