Fixed the networking issue (#200)

stack/vikunja.yml

@@ -54,10 +54,12 @@ services:
       - 3546:80
     volumes:
       - /portainer/Files/AppData/Config/Vikunja/nginx.conf:/etc/nginx/conf.d/default.conf:ro
+    networks:
+      - network
+    restart: unless-stopped
     depends_on:
       - api
       - frontend
-    restart: unless-stopped
 
 networks:
   network: