fix: pass media host url to nginx container

docker-compose.yml

@@ -14,6 +14,7 @@ services:
     environment:
       WORDPRESS_SITEURL:    ${WPSTACK_PROTOCOL}://${WPSTACK_DOMAIN}/${WPSTACK_URLPATH:-}
       WORDPRESS_SITE_TYPE:  ${WPSTACK_MULTISITE:-regular}
+      WPSTACK_MEDIA_HOST: ${WPSTACK_MEDIA_HOST:-}
     labels:
       caddy: ${WPSTACK_DOMAIN}
       caddy.reverse_proxy: "reverse-proxy:80"
@@ -64,7 +65,7 @@ services:
       MARIADB_DATABASE: ${DB_NAME}
     networks:
       - app-network
-      - db-network
+      - proxy-network
 
 volumes:
   db_data:
@@ -73,6 +74,4 @@ networks:
   app-network:
   proxy-network:
     external: true
-  db-network:
-    external: true