message: fix: handle submit_block rpc error
diff: @@ -138,11 +138,16 @@ impl Client {
  let future = self.send_submit_block_request(work_id, block);
  if self.config.block_on_submit {
  let ret: Result<Option<H256>, RpcError> = future.and_then(parse_response).wait();
  - if let Ok(hash) = ret {
  + match ret {
  + Ok(hash) => {
  if hash.is_none() {
  warn!(target: "miner", "submit_block failed {}", serde_json::to_string(block).unwrap());
  }
  }
  + Err(e) => {
  + error!(target: "miner", "rpc call submit_block error: {:?}", e);
  + }
  + }
  }
  }
  