Geo event-log pruning worker is not enabled/disabled by the sidekiq cron manager
Per https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4920#note_62824690
Geo::SidekiqCronWorker
should automatically enable the Geo::PruneEventLogWorker
when the server is turned into a primary, and disable it when turned into a secondary, but this doesn't happen at present.