Make dune-grid compile test more generic

cmake/Modules/Finddune-grid.cmake

@@ -41,7 +41,7 @@ find_opm_package (
 "#include <dune/grid/onedgrid.hh>
 int main (void) {
   Dune::OneDGrid grid(1, 0., 1.);
-  return grid.leafGridView().begin<0>() == grid.leafGridView().end<0>();
+  return grid.size(0);
 }
 "
   # config variables