remove num_class hyperparameter

[yash1]

num_class=1 gives error for binary classifcation task on sagemaker. Training does not complete. Removing it runs the training job successfully.

[djarpin]

XGBoost would normally ignore this parameter (which is why it never previously mattered that it was set incorrectly in the first place). We've recently added hyperparameter checks though, so thanks a lot for catching this and updating!