Add db network configuration for Django service in production override

docker-compose.prod.override.yml

@@ -30,6 +30,9 @@ services:
     volumes:
       - /mnt/data/feo-homepage/static:/app/static
       - /mnt/data/feo-homepage/media:/app/media
+    networks:
+      - default
+      - db
 
   nginx:
     image: nginx:1.23