[staggered][bugfix] Reinitialize maps in update

If update is called twice the connectivity map is wrong sinnce
we push additional entries in there, i.e. each node in the stencil
will appear twice.

This makes sure all vectors are correctly reinitalized in every update

dumux/discretization/staggered/freeflow/connectivitymap.hh

@@ -63,10 +63,12 @@ public:
         const auto numDofsCC = gridGeometry.gridView().size(0);
         const auto numDofsFace = gridGeometry.gridView().size(1);
         const auto numBoundaryFacets = gridGeometry.numBoundaryScvf();
-        cellCenterToCellCenterMap_.resize(numDofsCC);
-        cellCenterToFaceMap_.resize(numDofsCC);
-        faceToCellCenterMap_.resize(2*numDofsFace - numBoundaryFacets);
-        faceToFaceMap_.resize(2*numDofsFace - numBoundaryFacets);
+
+        // reinitialize maps
+        cellCenterToCellCenterMap_ = Map(numDofsCC);
+        cellCenterToFaceMap_ = Map(numDofsCC);
+        faceToCellCenterMap_ = Map(2*numDofsFace - numBoundaryFacets);
+        faceToFaceMap_ = Map(2*numDofsFace - numBoundaryFacets);
 
         // restrict the FvGeometry locally
         auto fvGeometry = localView(gridGeometry);