fixed missing macro check in ALL.hpp

include/ALL.hpp

@@ -670,7 +670,9 @@ template <class T, class W> void ALL<T,W>::get_neighbor_vertices(ALL_LB_t method
         case ALL_LB_t::UNSTRUCTURED:
             break;
         case ALL_LB_t::VORONOI:
+#ifdef ALL_VORONOI
             ((ALL_Voronoi_LB<T,W>*)balancer)->get_neighbor_vertices(nv);
+#endif
             break;
     }
 }