fix dump tree (#465)
fix dump tree (#465)


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