Remove old commented code

include/core/factor/factor_diff_drive.h

@@ -86,14 +86,6 @@ class FactorDiffDrive : public FactorAutodiff<FactorDiffDrive,
 
         VectorXs residual();
 
-//        /**
-//         * \brief Returns the jacobians computation method
-//         **/
-//        virtual JacobianMethod getJacobianMethod() const
-//        {
-//            return JAC_AUTO;
-//        }
-
     protected:
 
         Eigen::Vector3s calib_preint_;