eliminated shread_ptr dependency from optical flow gpu. It caused compilation errors.
eliminated shread_ptr dependency from optical flow gpu. It caused compilation errors.

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