LP#1662902: do not re-download EDI files that failed parsing

LP#1662902: do not re-download EDI files that failed parsing

Avoid fetching and creating edi_message entries for EDI messages that
the system cannot parse.

In the event parsing failed due to a temporary condition (e.g. Ruby
translator was not running), messages can be reprocessed by either
deleting the offending edi_message row or setting its status to 'retry'.

See previous commit ("LP#1662902: do not re-download EDI files that
failed processing") for a more detailed explanation.

Signed-off-by: Bill Erickson <berickxx@gmail.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>