message: chore: cleanup unused network error enum
diff: -use crate::ProtocolId;
  use p2p::{
  error::{
  DialerErrorKind, ListenErrorKind, ProtocolHandleErrorKind, SendErrorKind,
  @@ -16,13 +15,11 @@ pub type Result<T> = ::std::result::Result<T, Error>;
  #[derive(Debug)]
  pub enum Error {
  Peer(PeerError),
  - Protocol(ProtocolError),
  Io(IoError),
  P2P(P2PError),
  Addr(AddrError),
  Dial(String),
  PeerStore(PeerStoreError),
  - Shutdown,
  }
  #[derive(Debug)]
  @@ -45,23 +42,14 @@ pub enum PeerStoreError {
  pub enum PeerError {
  SessionExists(SessionId),
  PeerIdExists(PeerId),
  - NotFound(PeerId),
  NonReserved,
  Banned,
  ReachMaxInboundLimit,
  ReachMaxOutboundLimit,
  }
  -#[derive(Debug)]
  -pub enum ProtocolError {
  - NotFound(ProtocolId),
  - DisallowRegisterTimer,
  - Duplicate(ProtocolId),
  -}
  -
  #[derive(Debug)]
  pub enum AddrError {
  - InvalidPeerId,
  MissingIP,
  MissingPort,
  }
  @@ -84,12 +72,6 @@ impl From<IoError> for Error {
  }
  }
  -impl From<ProtocolError> for Error {
  - fn from(err: ProtocolError) -> Error {
  - Error::Protocol(err)
  - }
  -}
  -
  impl From<P2PError> for Error {
  fn from(err: P2PError) -> Error {
  Error::P2P(err)
  @@ -144,12 +126,6 @@ impl Display for PeerError {
  }
  }
  -impl Display for ProtocolError {
  - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  - write!(f, "{:?}", self)
  - }
  -}
  -
  impl Display for P2PError {
  fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
  write!(f, "{:?}", self)
  