error when train pnet

[yja1]

in dataset.py : size = (uniform(-1.0, 1.0) * sigma + 1) * face_max_size when size is small,the crop_box width or height will be zero. then cause error on: crop_img_np = img_np[crop_box[1]:crop_box[3], crop_box[0]:crop_box[2], :]