`config/schedule.rb` defines entries for cron jobs. Every five minutes
it insert several delayed jobs via `script/enqueue`. A recent upgrade of
Postgresql (a year or two ago) made that script noisy. Every time we
insert a delayed job with that script it outputs:
INSERT 0 1
Standard output like this is seen as error message by cron an forwarded
to the unix user's local mailbox in `/var/mail/openfoodnetwork`. This
file grows over time and accumulates tens of thousands of error
messages, hiding any important failures.
This patch makes inserting delayed jobs quiet. A failure is still
reported.
