Far future start dates (with no end dates) throw error 2309

[pauln]

If a module is created (or presumably updated) with no due or cutoff date, the turnitin_get_module_dates() function will set the dtdue parameter to a date 6 months from now. If the start date is more than six months into the future, it triggers the following error (which causes a backlog of events in the queue, as this event never gets processed "successfully"):

Error: 2309 When creating your assignment, please make sure that the post date is on or after the start date of the assignment.