Added some tweaks to 'model.xml' file

Change-Id: Ide7ba56d53c9565e0cceb6276ee07ecf9545f07b
Reviewed-on: https://gerrit.libreoffice.org/11473
Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Miklos Vajna <vmiklos@collabora.co.uk>