Make Richardson default istl precon

amdis/linearalgebra/istl/PreconCreator.hpp

@@ -249,7 +249,6 @@ namespace AMDiS
       auto jacobi = new PreconCreator<Dune::SeqJac<M,X,Y>>;
       Map::addCreator("diag", jacobi);
       Map::addCreator("jacobi", jacobi);
-      Map::addCreator("default", jacobi);
 
       auto gs = new PreconCreator<Dune::SeqGS<M,X,Y>>;
       Map::addCreator("gs", gs);
@@ -266,6 +265,7 @@ namespace AMDiS
 
       auto richardson = new PreconCreator<Dune::Richardson<X,Y>>;
       Map::addCreator("richardson", richardson);
+      Map::addCreator("default", richardson);
 
       auto solver = new PreconCreator<tag::solver>;
       Map::addCreator("solver", solver);