Adaptations to docker-compose V2

Test env now supports both docker-compose V1 and V2

Issue-ID: NONRTRIC-618

Signed-off-by: BjornMagnussonXA <bjorn.magnusson@est.tech>
Change-Id: I6a5717b6dce64086123cc5575ef45f9e299cd7e3
diff --git a/test/simulator-group/mrstub/docker-compose.yml b/test/simulator-group/mrstub/docker-compose.yml
index a1c96c0..608f5c8 100644
--- a/test/simulator-group/mrstub/docker-compose.yml
+++ b/test/simulator-group/mrstub/docker-compose.yml
@@ -18,8 +18,8 @@
 version: '3.0'
 networks:
   default:
-    external:
-      name: ${DOCKER_SIM_NWNAME}
+    external: true
+    name: ${DOCKER_SIM_NWNAME}
 services:
   mr-stub:
     networks: