Club Log: on a failed batch, log the callsign#id of every QSO in it so a
per-record rejection (e.g. a field value nginx's WAF blocks with a 403) can
actually be located instead of hiding behind "batch FAILED".
FCC ULS: catch the maintenance bounce before following it. data.fcc.gov
redirects to www.fcc.gov/system-maintenance during maintenance windows, and
that page then HTTP/2-stream-errors — which surfaced as a cryptic
INTERNAL_ERROR. Detect the redirect and return "try again later".
rouggy