Sidekiq / sending Email digests fails: MissingTranslationData

Same problem here since a while :

Jobs::HandledExceptionWrapper: Wrapped I18n::MissingTranslationData: translation missing: en.time.formats.short

Seems related to Email failed on V1.2.3

Upgrading to v1.3.5 and then to v1.4.0.beta9 does not fix this issue.