fdo#71785:  File hangs LibreOffice on Save

Problem Description: While saving the file LO shows the error
"This file could not be save".
The root cause was memory leak.

Conflicts:
	sw/qa/extras/ooxmlexport/ooxmlexport.cxx
Reviewed on:
	https://gerrit.libreoffice.org/6850

(cherry picked from commit 0f6240fa92c443f66441545438821c02b3412486)
Signed-off-by: Andras Timar <andras.timar@collabora.com>

Conflicts:
	sw/qa/extras/ooxmlexport/ooxmlexport.cxx

Change-Id: Iacc185780c14760056a7d690eb113d4dde1de034