replace uses of double checked locking pattern and
rtl::Static

Change-Id: I479d9d94f652b4fb4c67388405823a5f4e2b6ed4
Reviewed-on: https://gerrit.libreoffice.org/38690Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>