grafana: changed authentication name

Author: arodier

roles/grafana/templates/nginx.conf

@@ -50,7 +50,7 @@ server
 
     # Basic authentication
     # Do not change the realm, as this would reveal the presence of grafana
-    auth_pam $authentication;
+    auth_pam {{ network.domain }};
     auth_pam_service_name "nginx";
 
     proxy_set_header X-REMOTE-USER $remote_user;