[PL] BC; Constify a function argument.

ProcessLib/BoundaryCondition/NeumannBoundaryConditionLocalAssembler.h

@@ -33,7 +33,7 @@ public:
     NeumannBoundaryConditionLocalAssembler(
         MeshLib::Element const& e,
         std::size_t const local_matrix_size,
-        bool is_axially_symmetric,
+        bool const is_axially_symmetric,
         unsigned const integration_order,
         Parameter<double> const& neumann_bc_parameter)
         : Base(e, is_axially_symmetric, integration_order),