The rpc function can not work right.

[BlockRen]

Describe the bug The rpc function does not work.

Reproduction Code The rpc function in the nakama_grpc_client.dart

  @override
  Future<String?> rpc({
    required model.Session session,
    required String id,
    String? payload,
  }) async {
    final res = await _client.rpcFunc(api.Rpc(
      id: id,
      payload: payload,
    ));

    return res.payload;
  }

Above rpcFunc called in the rpc function, but the session was not used. So the server can not response rightly. We found the rpc in old version of the repository can work, but the new version does not work.

Expected behavior The rpc function is useful and expect to work rightly.