message: Switch back to std::copy_if in selectWarehouses
  Now that both collections are of the same type again, we can switch back
  to using `std::copy_if`.
diff: @@ -22,13 +22,7 @@ namespace
  const auto& warehouses = Utility<StructureManager>::get().structures<Warehouse>();
  std::vector<Warehouse*> output;
  - for (auto warehouse : warehouses)
  - {
  - if (predicate(warehouse))
  - {
  - output.push_back(warehouse);
  - }
  - }
  + std::copy_if(warehouses.begin(), warehouses.end(), output.end(), predicate);
  return output;
  }
  