[Satellite6] ListenOnCandlepinEvents task stopped due to "410 Gone" error

Issue

• Actions::Candlepin::ListenOnCandlepinEvents task suddenly stopped (went into paused/error state) with error:

Katello::Resources::Candlepin::Consumer: 410 Gone {"displayMessage":"Unit 54151fcb-df25-418c-9b40-d3d218c58c89 has been deleted","requestUuid":"04dbfeda-75cb-4ffa-ad9f-9f4c818fc868","deletedId":"54151fcb-df25-418c-9b40-d3d218c58c89"} (GET /candlepin/consumers/54151fcb-df25-418c-9b40-d3d218c58c89)

• no such consumer / katello system is present in Satellite at all