Correctly handle existing instance running

src/ckpool.c

@@ -2126,6 +2126,8 @@ int main(int argc, char **argv)
 		}
 	}
 
+	if (!ckp.handover)
+		manage_old_child(&ckp, &ckp.main);
 	write_namepid(&ckp.main);
 	open_process_sock(&ckp, &ckp.main, &ckp.main.us);
 	launch_logger(&ckp.main);