Switch ocis NAS share from SMB to NFS Docker named volume

Replace /mnt/nas_owncloud CIFS bind mount with nas_owncloud external
NFS volume (192.168.1.192:/mnt/user/owncloud). Removes dependency on
systemd CIFS automount units.

ocis/docker-compose.yml

@@ -26,13 +26,17 @@ services:
       - PROXY_CSP_CONFIG_FILE_LOCATION=/etc/ocis/csp.yaml
     volumes:
       - /srv/ocis/data:/var/lib/ocis
-      - /mnt/nas_owncloud:/var/lib/ocis/storage/users
+      - nas_owncloud:/var/lib/ocis/storage/users
       - /srv/ocis/config:/etc/ocis
     ports:
       - 9200:9200
     networks:
       - npm-network
 
+volumes:
+  nas_owncloud:
+    external: true
+
 networks:
   npm-network:
     external: true