bug hotfix

src/processor/processor_tracker_feature.cpp

@@ -108,8 +108,8 @@ unsigned int ProcessorTrackerFeature::processKnown()
                 // Remove this feature from many places:
                 matches_last_from_incoming_          .erase (*ftr_inc_it);  // remove match
                 track_matrix_                        .remove(*ftr_inc_it);  // remove from track matrix
-                ftr_inc_it = known_features_incoming_.erase(ftr_inc_it);    // remove from known features list
                 (*ftr_inc_it)->                       remove();             // remove from wolf tree
+                ftr_inc_it = known_features_incoming_.erase(ftr_inc_it);    // remove from known features list
             }
             else
                 ftr_inc_it++;