just because use_count is > 2, doesn't mean we have two simultaneous
writes, could be 2 readers and a writer

Change-Id: Ife7fc91ff2e597e6bb847460f46bdde954e63e4f
Reviewed-on: https://gerrit.libreoffice.org/55695Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>