message: Update grpc-network-client.ts
diff: @@ -61,7 +61,7 @@ class GRPCNetworkClient implements Networking.NetworkClient {
  this.grpcClient.submitSignedTransaction(
  submitSignedTransactionRequest,
  (error, response): void => {
  - if (error != null || response == null) {
  + if (error !== null || response === null) {
  reject(error);
  return;
  }
  