[cleanup] change boundarytypes

exercises/exercise-basic/injection2pniproblem.hh

@@ -60,7 +60,7 @@ class Injection2PNIProblem : public PorousMediumFlowProblem<TypeTag>
     using Scalar = GetPropType<TypeTag, Properties::Scalar>;
     using Indices = typename GetPropType<TypeTag, Properties::ModelTraits>::Indices;
     using PrimaryVariables = GetPropType<TypeTag, Properties::PrimaryVariables>;
-    using BoundaryTypes = GetPropType<TypeTag, Properties::BoundaryTypes>;
+    using BoundaryTypes = Dumux::BoundaryTypes<GetPropType<TypeTag, Properties::ModelTraits>::numEq()>;
     using FVGridGeometry = GetPropType<TypeTag, Properties::GridGeometry>;
     using FVElementGeometry = typename GetPropType<TypeTag, Properties::GridGeometry>::LocalView;
     using FluidSystem = GetPropType<TypeTag, Properties::FluidSystem>;