Created mailmerge output document was not using current printer settings,
which can be taken not only from settings, but overriden by currently
opened template.

Change-Id: Ic127dcbfbe8f1e80073b06ecb399100344f4c01d
Reviewed-on: https://gerrit.libreoffice.org/54358Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>
Tested-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>