VO mode BUG🐛

[theyunfeng]

VO模式下在特征点很少的时候后端会报错 /usr/include/eigen3/Eigen/src/Core/Redux.h:413: typename Eigen::internal::traits::Scalar Eigen::DenseBase::redux(const Func&) const [with BinaryOp = Eigen::internal::scalar_max_op<double, double>; Derived = Eigen::CwiseUnaryOp<Eigen::internal::scalar_abs_op, const Eigen::Matrix<double, -1, -1> >; typename Eigen::internal::traits::Scalar = double]: Assertion `this->rows()>0 && this->cols()>0 && "you are using an empty matrix"' failed. 经过调试发现问题在当marginalization_flag == MARGIN_OLD时，代码在下图位置marginalize() 函数中崩溃，且感觉VO模式貌似不是很准，请问是参数问题吗？