Remove checks for label when loading dataset from binary file because label is ignored in that case (#4737)
Remove checks for label when loading dataset from binary file because label is ignored in that case (#4737)


henry0312/LightGBM,henry0312/LightGBM,henry0312/LightGBM,microsoft/LightGBM,microsoft/LightGBM,henry0312/LightGBM,microsoft/LightGBM,microsoft/LightGBM,henry0312/LightGBM,microsoft/LightGBM