message: Fix update message in config server
diff: @@ -86,13 +86,13 @@ behavior config_serv_impl(stateful_actor<kvstate>* self) {
  // we never put a nullptr in our map
  auto subscriber = actor_cast<actor>(subscriber_ptr);
  if (subscriber != self->current_sender())
  - self->send(subscriber, update_atom::value, key, vp.second);
  + self->send(subscriber, update_atom::value, key, vp.first);
  }
  // also iterate all subscribers for '*'
  for (auto& subscriber : self->state.data[wildcard].second)
  if (subscriber != self->current_sender())
  self->send(actor_cast<actor>(subscriber), update_atom::value,
  - key, vp.second);
  + key, vp.first);
  },
  // get a key/value pair
  [=](get_atom, std::string& key) -> message {
  