Update docker-compose.yml

Updated to Docker Compose V2

docker/docker-compose.yml

@@ -1,5 +1,4 @@
-version: '3'
-
+---
 services:
   backend:
     image: 4gray/iptvnator-backend:latest
@@ -14,4 +13,4 @@ services:
       - "4333:80"
     environment:
       - BACKEND_URL=http://192.168.172.67:7333 # this one should match with the address of the backend service
-      
+