lok: masterpage: don't switch page on mode change
Go back to the last used page when closing MasterPage.
There was a bug when one user was in MasterPage mode and
other switched page - then on close we opened other user
page.
Change-Id: I02f3b36429a62b855b215803d6684b3382228326
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/142740
Tested-by: Jenkins CollaboraOffice <jenkinscollaboraoffice@gmail.com>
Reviewed-by: Ashod Nakashian <ash@collabora.com>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/142967
Tested-by: Jenkins
Reviewed-by: Szymon Kłos <szymon.klos@collabora.com>