message: network-grpc: terser Display impl of client::Error
  In accordance with conventions elsewhere, don't format the underlying
  connection error that is also available through error chaining.
diff: @@ -442,7 +442,7 @@ impl From<ConnectError<io::Error>> for Error {
  impl fmt::Display for Error {
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  match self {
  - Error::Connect(e) => write!(f, "connection error: {}", e),
  + Error::Connect(_) => write!(f, "failed to establish connection"),
  }
  }
  }
  