if we're going to be deleting a temporary file, there is no point
flushing it on close, which has a measureable cost
This takes my load time from 17s to 16s
Change-Id: I2fce7eeaf0ce9fef826b4ce9a1a4d4c8114cac76
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/117607
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
