fix corner 2D

@joanvallve can you please check this PR ?

src/feature_corner_2D.cpp

@@ -4,7 +4,7 @@
 namespace wolf {
 
 FeatureCorner2D::FeatureCorner2D(const Eigen::Vector4s & _measurement, const Eigen::Matrix4s & _meas_covariance) :
-    FeatureBase("CORNER", _measurement, _meas_covariance)
+    FeatureBase("CORNER 2D", _measurement, _meas_covariance)
 {
     //std::cout << "feature: "<< _measurement.transpose() << std::endl;
 }