Add COLLECTOR_HOST_ID env var to hubspoke example

Added COLLECTOR_HOST_ID environment variable to hubspoke example

docker/example.hubspoke.docker-compose.yml

@@ -40,6 +40,7 @@ services:
       - '/run/udev:/run/udev:ro'
     environment:
       COLLECTOR_API_ENDPOINT: 'http://web:8080'
+      COLLECTOR_HOST_ID: 'scrutiny-collector-hostname'
     depends_on:
       web:
         condition: service_healthy