enrol_flatfile implements wrong provider

It has the enrol_flatfile DB table

I ran the enrolment flatfile scheduled task, and confirmed that indeed the entry persists in the table beyond the run time of the task. I'd expect to allow for future enrolments to be triggered. You need a future date for this to occur.

If there's any data sitting in the table after a cron run completes, then we should be reporting this as it's more than just temp data in such cases.