Unhandled Acme::Client::Error::BadCSR

Sometimes we fail to obtain let's encrypt certificates because of BadCSR error. This needs investigation.

See error in Sentry: https://new-sentry.gitlab.net/organizations/gitlab/issues/885881/?environment=gprd&project=3&query=stage%3Amain+type%3Asidekiq&referrer=issue-stream&statsPeriod=14d&stream_index=11 , or search for Acme::Client::Error::BadCSR there.