docker: remove unneeded network-config

docker-compose.yml

@@ -13,13 +13,8 @@ services:
     environment:
       WEB_DOCUMENT_ROOT: /app/public
       XDEBUG_REMOTE_HOST: marvin
-    links:
-      - dbserver
     depends_on:
       - dbserver
-    networks:
-      - backend
-    restart: on-failure
   dbserver:
     image: mariadb:latest
     environment:
@@ -27,14 +22,9 @@ services:
       MYSQL_DATABASE: ${DB_DATABASE}
       MYSQL_USER: ${DB_USERNAME}
       MYSQL_PASSWORD: ${DB_PASSWORD}
-    networks:
-      - backend
     restart: on-failure
     ports:
       - "3306:3306"
     volumes:
       - ./.local/db:/var/lib/mysql
       - ./container/db/:/docker-entrypoint-initdb.d
-networks:
-  backend:
-    driver: bridge