java: ByteArrayConstructor should graciously handle existing byte arrays

The method ByteArrayConstructor#construct(Object[]) fails with a ClassCastException if the argument is already a byte array. This situation should be handled by introducing an instanceof type check:

if(args.length == 1){
  if(args[0] instanceof byte[]){
    return args[0];
  }
  // Proceed as usual
}

I’ve come across pickled xgboost.sklearn.XGBRegressor object instances (using Python 3.4) where the builtins.bytearray is already a byte array. For example, the following commit contains such joblib dump file XGBAuto.pkl: https://github.com/jpmml/jpmml-sklearn/commit/bc022a3c6353a4eec5f377e6937237c73334c445

[irmen]

new versions have been relased to maven and nuget.

[vruusmann]

I can confirm that the current Pyrolite version 4.12-SNAPSHOT works fine with my tests.