fix bilateral filter behavior when color_sigma == 0 and/or spatial_sigma == 0 (ticket #469)
fix bilateral filter behavior when color_sigma == 0 and/or spatial_sigma == 0 (ticket #469)

opencv/opencv,apavlenko/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,opencv/opencv,opencv/opencv