Ignore empty extra lines in train.txt

AlexeyAB

2018-05-29 ec766fc3f114dd4faaa3add500776a7bae957ba5

 src/image.c

@@ -536,7 +536,7 @@
         cvRectangle(show_img, pt1, pt2, color, width, 8, 0);
         if (ext_output)
            printf("\t(left_x: %4.0f   top_y: %4.0f   width: %4.0f   height: %4.0f)\n", 
               (float)left, (float)right, b.w*show_img->width, b.h*show_img->height);
               (float)left, (float)top, b.w*show_img->width, b.h*show_img->height);
         else
            printf("\n");
         cvRectangle(show_img, pt_text_bg1, pt_text_bg2, color, width, 8, 0);