fixed passing of communicator to balancing object

include/ALL.hpp

@@ -349,6 +349,7 @@ template <class T, class W> void ALL<T,W>::set_communicator(MPI_Comm comm)
     if (MPI_Topo_test(comm, &comm_type) == MPI_CART)
     {
         communicator = comm;
+        balancer->set_communicator(communicator);
     }
     else
     {
@@ -389,6 +390,7 @@ template <class T, class W> void ALL<T,W>::set_communicator(MPI_Comm comm)
 
             // transform temporary communicator to cartesian communicator
             MPI_Cart_create(temp_comm, balancer->get_dimension(), proc_grid_dim.data(), periods.data(), 0, &communicator);
+            balancer->set_communicator(communicator);
         }
         else
         {