Remove unnecessary label, update the explanation
of the buttons, and reduce the width of the
document recovery dialog.

Change-Id: I74081d8fd479de419c3be4456228e3415ccc0483
Reviewed-on: https://gerrit.libreoffice.org/27511Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>