fix index out of range in predictor.
fix index out of range in predictor.

Allardvm/LightGBM,olofer/LightGBM,Laurae2/LightGBM,microsoft/LightGBM,olofer/LightGBM,huanzhang12/LightGBM,huanzhang12/LightGBM,henry0312/LightGBM,Allardvm/LightGBM,wxchan/LightGBM,huanzhang12/LightGBM,olofer/LightGBM,wxchan/LightGBM,Laurae2/LightGBM,Allardvm/LightGBM,henry0312/LightGBM,henry0312/LightGBM,microsoft/LightGBM,henry0312/LightGBM,Laurae2/LightGBM,olofer/LightGBM,wxchan/LightGBM,Allardvm/LightGBM,Laurae2/LightGBM,wxchan/LightGBM,Laurae2/LightGBM,olofer/LightGBM,Allardvm/LightGBM,wxchan/LightGBM,microsoft/LightGBM,microsoft/LightGBM,huanzhang12/LightGBM,microsoft/LightGBM,huanzhang12/LightGBM,henry0312/LightGBM