JobScheduler should not crash if an order with a run time is added to a job chain that does not exist

<job  name="job1">
    <script  language="java:javascript">
        <![CDATA[
function spooler_process(){

   run_time = '<run_time ><weekdays ><day  day="1 2 3 4 5 6 7"> <period  single_start="10:00"/> </day></weekdays></run_time>';

   var order = spooler.create_order();
   order.run_time.xml=run_time;
   var job_chain = spooler.job_chain("xxx");
   job_chain.add_or_replace_order(order);


	return false;
}
        ]]>
    </script>

    <run_time />
</job>