message: Add explanation comment for hotfix.
diff: @@ -1791,6 +1791,8 @@ pub mod tests {
  params.insert("force", "true".to_string()); // because node_works test added fifth Node
  cmd.execute(&ctx, &params).unwrap();
  }
  + // There is no way to read upgrade transaction to be sure about completly write before sending next one.
  + // So just sleep agains other places where control read request is available
  ::std::thread::sleep(::std::time::Duration::from_secs(1));
  {
  let cmd = pool_upgrade_command::new();
  