Missing C# doc string for ChnageModelThreshold

[rauhs]

Linky:

machinelearning/src/Microsoft.ML.Data/TrainCatalog.cs

Lines 261 to 267 in 3f98485

	public BinaryPredictionTransformer<TModel> ChangeModelThreshold<TModel>(BinaryPredictionTransformer<TModel> model, float threshold)
	where TModel : class
	{
	if (model.Threshold == threshold)
	return model;
	return new BinaryPredictionTransformer<TModel>(Environment, model.Model, model.TrainSchema, model.FeatureColumnName, threshold, model.ThresholdColumn);
	}

[gvashishtha]

@frank-dong-ms

[frank-dong-ms-zz]

Fix has been checked in.