Remove "summary" logging

Remove "summary" logging

The "summary" was a list of failed downloads, and from what I gather,
it was intended to clue the admin of a possible disconnection problem.

Thing is, the implementation was rather bewilderingly large and
obtrusive, and now that we're going to have a Prometheus endpoint,
most likely replaceable by an elegant counter.

And I haven't implemented Prometheus yet, but I would definitely love to
stop running into this invasive code all over the place, thanks.