when in master view mode go straight to adding the master page to the
list of masters

Change-Id: I345ce30b44099cd546267fb2acae0b1cc8a73dbe
Reviewed-on: https://gerrit.libreoffice.org/44606Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>