message: remove user on logout
diff: @@ -88,7 +88,13 @@ blocks!{
  #[subscription]
  fn store_user() {
  - user().use_ref(|user| LocalStorage::insert(USER_STORAGE_KEY, user));
  + user().use_ref(|user| {
  + if let Some(user) = user {
  + LocalStorage::insert(USER_STORAGE_KEY, user);
  + } else {
  + LocalStorage::remove(USER_STORAGE_KEY);
  + }
  + });
  }
  #[update]
  