message: Eliminate temporary when loading MineVein data
diff: @@ -302,14 +302,11 @@ void Mine::deserialize(NAS2D::Xml::XmlElement* element)
  for (auto* vein = element->firstChildElement(); vein != nullptr; vein = vein->nextSiblingElement())
  {
  const auto veinDictionary = NAS2D::attributesToDictionary(*vein);
  -
  - MineVein mineVein{
  + mVeins.push_back({
  veinDictionary.get<int>("common_metals", 0),
  veinDictionary.get<int>("common_minerals", 0),
  veinDictionary.get<int>("rare_metals", 0),
  veinDictionary.get<int>("rare_minerals", 0),
  - };
  -
  - mVeins.push_back(mineVein);
  + });
  }
  }
  