message: retry if node is not ready yet
diff: @@ -55,7 +55,12 @@ fn main() {
  let (srv, events) = Services::new(endpoint, &base_dir, &baker);
  let chain_id = srv.client.get_chain_id().unwrap();
  let _ = srv.client.wait_bootstrapped().unwrap();
  - let constants = srv.client.get_constants().unwrap();
  + let constants = loop {
  + match srv.client.get_constants() {
  + Ok(v) => break v,
  + Err(_) => std::thread::sleep(std::time::Duration::from_millis(200)),
  + }
  + };
  srv.client.monitor_heads(&chain_id).unwrap();
  let log = srv.log.clone();
  