message: Add safeguard to MessageDeleteLuo to prevent rare crash
  We had a crash related to this on Ravenloft POTM. Not sure of the underlying cause, but adding a safeguard should prevent it from reoccuring.
diff: @@ -148,7 +148,8 @@ static void MessageDeleteLuo(CNWSMessage* msg, CLastUpdateObject* luo, CNWSPlaye
  bool bDelete = true;
  if (auto obj = Utils::AsNWSObject(Utils::GetGameObject(luo->m_nId)))
  {
  - if (obj->GetArea() == player->GetGameObject()->GetArea())
  + auto pgo = player->GetGameObject();
  + if (pgo && (obj->GetArea() == pgo->GetArea()))
  bDelete = false;
  }
  