Make sure admins receive an error in case of exception in custom management command

[niconoe]

On dev, due to recent changes in terms of multilanguages, the error notification emails were not sent anymore in English.

An exception was thrown by the management command, but it was not reported to the admin because it happened outside the request/response cycle. It would be good to improve that for robustness, possible approach at: https://mpcabd.xyz/make-django-management-commands-send-errors-email-admins/