ebos: always call the loadBalance() method of the grid again

It was disabled because Dune::CpGrid::loadBalance() dropped all cells
which were disconnected from the main part of the grid. since the
problem was fixed in https://github.com/OPM/opm-grid/pull/245, let's
re-enable load balancing.

applications/ebos/eclcpgridmanager.hh

@@ -134,18 +134,10 @@ public:
         int mpiSize = 1;
         MPI_Comm_rank(MPI_COMM_WORLD, &mpiRank);
         MPI_Comm_size(MPI_COMM_WORLD, &mpiSize);
-        if (mpiSize > 1) {
-            // TODO: always load balance as soon as Dune::CpGrid works correctly for the
-            // Norne deck!
-            if (mpiRank == 0)
-                std::cerr << "Since Dune::CpGrid is buggy when load balancing, "
-                          << "ebos currently disables parallelism when using Dune::CpGrid.\n";
-            std::exit(1);
 
-            // distribute the grid and switch to the distributed view.
-            grid_->loadBalance();
-            grid_->switchToDistributedView();
-        }
+        // distribute the grid and switch to the distributed view.
+        grid_->loadBalance();
+        grid_->switchToDistributedView();
 #endif
 
         cartesianIndexMapper_ = new CartesianIndexMapper(*grid_);