OBookmarkContainer actually re-uses the reference count of
ODatabaseSource, so converting ODatabaseSource::m_aBookmark to Reference
created a cycle, which somehow causes the dataloss, because evidently
something as important as storing the data must be done in the
destructor.

(regression from 2660d24a)

(cherry picked from commit 96ae2a33)

tdf#114596 compilerplugins: add exception to [loplugin:refcounting]
(cherry picked from commit e80da608)

Change-Id: I4cad01dc9cdaf405c1eb31d6c0e161eb6712b78f
Reviewed-on: https://gerrit.libreoffice.org/49025Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>