add a variable for traefik entrypoint

templates/compose/grafana-prometheus.yml.j2

@@ -61,7 +61,7 @@ services:
       traefik.http.routers.grafana.rule: Host(`{{ grafana_domain|default(omit) }}`)
       traefik.http.routers.grafana.tls: true
       traefik.http.routers.grafana.tls.certresolver: letsencrypt
-      traefik.http.routers.grafana.entrypoints: websecure
+      traefik.http.routers.grafana.entrypoints: "{{ grafana_traefik_entrypoint }}"
       traefik.http.services.grafana.loadbalancer.server.port: 3000
 {% else %}
     ports: