message: add move for gcc 4.8
diff: @@ -33,7 +33,7 @@ unique_ptr<PhysicalOperator> PhysicalPlanGenerator::CreatePlan(LogicalSimple &op
  auto result = make_unique<PhysicalVacuum>(unique_ptr_cast<ParseInfo, VacuumInfo>(move(op.info)),
  op.estimated_cardinality);
  result->children.push_back(move(child));
  - return result;
  + return move(result);
  }
  case LogicalOperatorType::LOGICAL_LOAD:
  return make_unique<PhysicalLoad>(unique_ptr_cast<ParseInfo, LoadInfo>(move(op.info)), op.estimated_cardinality);
  