fix obvious copy+paste typo in computeDistance()
fix obvious copy+paste typo in computeDistance()

(with this else-branch, argument contour2 would not be used at all)
apavlenko/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv