Did a small change to bool Dialog::Close() in dialog.cxx file. Patch No. 2

Change-Id: I5268e77bef2225308e9d01831c7b09de19c3ded9
Reviewed-on: https://gerrit.libreoffice.org/21212Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Michael Meeks <michael.meeks@collabora.com>