use a dummy database name for the default postgres database name
use a dummy database name for the default postgres database name

For some reason the docker image does not setup the permissions correctly,
by using a different name the nextcloud installer will create the database instead
with the correct permissions

Signed-off-by: Robin Appelman <474ee9ee179b0ecf0bc27408079a0b15eda4c99d@icewind.nl>

andreas-p/nextcloud-server,andreas-p/nextcloud-server,andreas-p/nextcloud-server,nextcloud/server,andreas-p/nextcloud-server,nextcloud/server,nextcloud/server,andreas-p/nextcloud-server,nextcloud/server