message: stitching: fix l_gains data type from Eigen solver (float / double)
diff: @@ -180,10 +180,13 @@ void GainCompensator::feed(const std::vector<Point> &corners, const std::vector<
  #endif
  eigen_x = solver.solve(eigen_b);
  - eigen2cv(eigen_x, l_gains);
  + Mat_<float> l_gains_float;
  + eigen2cv(eigen_x, l_gains_float);
  + l_gains_float.convertTo(l_gains, CV_64FC1);
  #else
  solve(A, b, l_gains);
  #endif
  + CV_CheckTypeEQ(l_gains.type(), CV_64FC1, "");
  gains_.create(num_images, 1);
  for (int i = 0, j = 0; i < num_images; ++i)
  