which is the Gnome default app for ḱey management

Change-Id: I4c27074f83538640fb1729c5cfddd96981d35f40
Reviewed-on: https://gerrit.libreoffice.org/39288Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Katarina Behrens <Katarina.Behrens@cib.de>
(cherry picked from commit f65f34d6)
Reviewed-on: https://gerrit.libreoffice.org/41158