message: test: replace is_err in test
diff: @@ -22,7 +22,8 @@ fn test_accept_inbound_peer_in_reserve_only_mode() {
  // reserved_only mode: only accept reserved_peer
  let mut peers = PeerRegistry::new(3, 3, true, vec![reserved_peer.clone()]);
  - assert!(peers
  + assert_eq!(
  + peers
  .accept_peer(
  PeerId::random(),
  addr.clone(),
  @@ -30,7 +31,9 @@ fn test_accept_inbound_peer_in_reserve_only_mode() {
  SessionType::Inbound,
  peer_store.as_mut(),
  )
  - .is_err());
  + .unwrap_err(),
  + PeerError::NonReserved
  + );
  peers
  .accept_peer(
  