Add owncloud default vars to role

roles/owncloud/defaults/main.yml

+secret_root: '{{ inventory_dir | realpath }}'
+secret_name: 'secret'
+secret: '{{ secret_root + "/" + secret_name }}'
+
+owncloud_domain: "cloud.{{ domain }}"
+owncloud_db_username: owncloud
+owncloud_db_password: "{{ lookup('password', secret + '/' + 'owncloud_db_password', length=32) }}"
+owncloud_db_database: owncloud