Update ports yet again because something is already running on the VPS

Yes, we are sure this is not our application running twice, this is some other user's app

docker-compose.yml

@@ -26,7 +26,7 @@ services:
   frontend:
     build: ./frontend
     ports:
-      - "80:80"
+      - "81:80"
     depends_on:
       - backend
     restart: on-failure