use std::remove_const in any.hh/any_cast

dune/fufem/any.hh

@@ -207,7 +207,7 @@ T any_cast(any& operand)
 template<typename T>
 const T* any_cast(const any* operand)
 {
-    return operand->template get<typename Dune::remove_const<T>::type>();
+    return operand->template get<typename std::remove_const<T>::type>();
 }
 
 
@@ -220,7 +220,7 @@ const T* any_cast(const any* operand)
 template<typename T>
 T* any_cast(any* operand)
 {
-    return operand->template get<typename Dune::remove_const<T>::type>();
+    return operand->template get<typename std::remove_const<T>::type>();
 }