snibox: sort out networks

snibox.yml

@@ -7,6 +7,8 @@ services:
       - "${SNIBOX_EXTERNAL_PORT}:${SNIBOX_INTERNAL_PORT}"
     volumes:
       - static-files:/var/www/html
+    networks:
+      - default
     depends_on:
       - backend
 
@@ -34,6 +36,7 @@ services:
     volumes:
       - static-files:/app/public
     networks:
+      - default
       - postgres
     # depends_on:
     #   - database
@@ -44,6 +47,7 @@ services:
     #     - pg-data:/var/lib/postgresql/data
 
 networks:
+  default:
   postgres:
     external: true