The schedule for Certificate Enrollment Gateway to remove expired ACMEv2 orders from the internal database. The value must be a cron schedule expression in the following format:
<second> <minute> <hour> <day-of-month> <month> <day-of-week>
For example, to run the cron job every 1 hour:
0 0 * ? * *
Mandatory: No. If this setting is absent, Certificate Enrollment Gateway removes expired ACMEv2 orders every 1 hour.