Mailing list page has invalid SSL cert

[ckonstanski]

https://lists.supervisord.org/mailman/listinfo/supervisor-users is unreachable in browsers with up-to-date security restrictions.

lists.supervisord.org uses an invalid security certificate. The certificate is not trusted because it is self-signed. The certificate is not valid for the name lists.supervisord.org. Error code: SEC_ERROR_UNKNOWN_ISSUER

[mnaberez]

@mcdonc owns the domain and runs the mailing list server. Maybe he could get a free Let's Encrypt certificate for it. @mcdonc?