message: cache_new_schema should check if the realm is closed, otherwise it will throw when it reaches verify_open
diff: @@ -429,6 +429,7 @@ void Realm::add_schema_change_handler()
  void Realm::cache_new_schema()
  {
  + if (!is_closed()) {
  auto new_version = transaction().get_version_of_current_transaction().version;
  if (m_new_schema)
  m_coordinator->cache_schema(std::move(*m_new_schema),
  @@ -438,6 +439,7 @@ void Realm::cache_new_schema()
  m_schema_transaction_version = new_version;
  m_new_schema = util::none;
  }
  +}
  void Realm::translate_schema_error()
  {
  