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

Change-Id: I2ba0b9b44971166bd79527b52745f3c40dc14387
Reviewed-on: https://gerrit.libreoffice.org/66490
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>