message: fix: estimateChessboardSharpness triggers out of range test
  Problem is that iter1 += tcols, iter2 += tcols are called without check.
  row < trows - 1 check is processed after increment in "for" statements.
diff: @@ -3323,13 +3323,15 @@ cv::Scalar Chessboard::Board::calcEdgeSharpness(cv::InputArray _img,float rise_d
  // build vertical lines
  for(int col = 1;col< tcols-1;++col)
  {
  - std::vector<cv::Point2f>::const_iterator iter1 = centers.begin()+col;
  - std::vector<cv::Point2f>::const_iterator iter2 = iter1+tcols;
  - for(int row= 0;row<trows-1;++row,iter1+=tcols,iter2+=tcols)
  - pairs.push_back(std::make_pair(*iter1,*iter2));
  + // avoid using iterators to not trigger out of range
  + int i1 = col;
  + int i2 = i1 + tcols;
  + for (int row = 0; row < trows - 1; ++row, i1 += tcols, i2 += tcols)
  + {
  + pairs.push_back(std::make_pair(centers[i1], centers[i2]));
  + }
  }
  }
  -
  // calc edge response for each line
  cv::Rect rect(0,0,img.cols,img.rows);
  