message: Fix DpSeamFinder::hasOnlyOneNeighbor
  std::lower_bound is linear for set
diff: @@ -554,8 +554,8 @@ void DpSeamFinder::computeGradients(const Mat &image1, const Mat &image2)
  bool DpSeamFinder::hasOnlyOneNeighbor(int comp)
  {
  std::set<std::pair<int, int> >::iterator begin, end;
  - begin = lower_bound(edges_.begin(), edges_.end(), std::make_pair(comp, std::numeric_limits<int>::min()));
  - end = upper_bound(edges_.begin(), edges_.end(), std::make_pair(comp, std::numeric_limits<int>::max()));
  + begin = edges_.lower_bound(std::make_pair(comp, std::numeric_limits<int>::min()));
  + end = edges_.upper_bound(std::make_pair(comp, std::numeric_limits<int>::max()));
  return ++begin == end;
  }
  