Tell people what to do when running in debug mode

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@2284 d4fa192b-c00b-0410-8231-f00ffab90ce4

bin/varnishd/mgt_child.c

@@ -420,6 +420,9 @@ mgt_run(int dflag, const char *T_arg)
 	fprintf(stderr, "rolling(2)...\n");
 	if (!dflag)
 		start_child();
+	else
+		fprintf(stderr,
+		    "Debugging mode, enter \"start\" to start child\n");
 
 	i = ev_schedule(mgt_evb);
 	fprintf(stderr, "ev_schedule = %d\n", i);