Fixed compilation without OpenMP (#255)
Fixed compilation without OpenMP (#255)


huanzhang12/lightgbm-gpu,huanzhang12/lightgbm-gpu,Laurae2/LightGBM,huanzhang12/LightGBM,Laurae2/LightGBM,olofer/LightGBM,cbecker/LightGBM,Allardvm/LightGBM,wxchan/LightGBM,olofer/LightGBM,huanzhang12/lightgbm-gpu,henry0312/LightGBM,fstonezst/LightGBM,microsoft/LightGBM,Laurae2/LightGBM,Laurae2/LightGBM,sightmachine/LightGBM,Allardvm/LightGBM,wxchan/LightGBM,sightmachine/LightGBM,huanzhang12/lightgbm-gpu,microsoft/LightGBM,huanzhang12/LightGBM,cbecker/LightGBM,sightmachine/LightGBM,Allardvm/LightGBM,fstonezst/LightGBM,olofer/LightGBM,huanzhang12/lightgbm-gpu,microsoft/LightGBM,huanzhang12/LightGBM,henry0312/LightGBM,fstonezst/LightGBM,wxchan/LightGBM,henry0312/LightGBM,olofer/LightGBM,cbecker/LightGBM,fstonezst/LightGBM,huanzhang12/LightGBM,henry0312/LightGBM,microsoft/LightGBM,Laurae2/LightGBM,wxchan/LightGBM,sightmachine/LightGBM,Allardvm/LightGBM,fstonezst/LightGBM,Allardvm/LightGBM,henry0312/LightGBM,huanzhang12/LightGBM,wxchan/LightGBM,olofer/LightGBM,cbecker/LightGBM,microsoft/LightGBM