message: Lift nullptr check outside of readRccRobots
  The nullptr check fits more logically with the other similar check
  outside of `readRccRobots`. Besides, this method doesn't even really
  need to know about XmlAttributes.
diff: @@ -56,8 +56,6 @@ static void loadResorucesFromXmlElement(NAS2D::Xml::XmlElement* element, Storabl
  static void readRccRobots(NAS2D::Xml::XmlAttribute* attr, RobotCommand& robotCommand, RobotPool& pool)
  {
  - if (!attr) { return; }
  -
  for (const auto& string : NAS2D::split(attr->value(), ','))
  {
  const auto robotId = NAS2D::stringTo<int>(string);
  @@ -500,9 +498,13 @@ void MapViewState::readStructures(Xml::XmlElement* element)
  {
  auto robotsElement = structureElement->firstChildElement("robots");
  if (robotsElement)
  + {
  + const auto robotsAttribute = robotsElement->firstAttribute();
  + if (robotsAttribute)
  {
  auto& robotCommand = *static_cast<RobotCommand*>(&structure);
  - readRccRobots(robotsElement->firstAttribute(), robotCommand, mRobotPool);
  + readRccRobots(robotsAttribute, robotCommand, mRobotPool);
  + }
  }
  }
  