[tech] gitlab.ucc's SSL certificate

[David Adam]

Cert Spotter is warning me that the SSL certificate for gitlab.ucc.asn.au 
expires next week. The Let's Encrypt machinery should have renewed it by 
now. Is someone able to take a look?

>From memory, I converted all machines including Gitlab to the official 
certbot client (instead of using acmetool), so `certbot certificates` 
might be a good command to start with.

See also https://wiki.ucc.asn.au/SSLCertificates for how things should be 
set up.

[DAA]