[md][facet][box] Fix LowDimCouplingContext

* resize local objects
* fixes clang error

dumux/multidomain/facet/box/couplingmanager.hh

@@ -158,9 +158,9 @@ class FacetCouplingManager<MDTraits, CouplingMapper, bulkDomainId, lowDimDomainI
         template<bool s = bulkIsSurfaceGrid, std::enable_if_t<s, int> = 0>
         void resize(std::size_t numEmbedments)
         {
-            lowDimContext_.bulkFvGeometries.resize(numEmbedments, nullptr);
-            lowDimContext_.bulkElemVolVars.resize(numEmbedments, nullptr);
-            lowDimContext_.bulkElemFluxVarsCache.resize(numEmbedments, nullptr);
+            bulkFvGeometries.resize(numEmbedments, nullptr);
+            bulkElemVolVars.resize(numEmbedments, nullptr);
+            bulkElemFluxVarsCache.resize(numEmbedments, nullptr);
             bulkElemBcTypes.resize(numEmbedments);
         }