SHA1 certificates

[JaneX8]

As stated here: #2884

[JaneX8]

• https://konklone.com/post/why-google-is-hurrying-the-web-to-kill-sha-1
• https://blog.mozilla.org/security/2014/09/23/phasing-out-certificates-with-sha-1-based-signature-algorithms/
• https://cs.auscert.org.au/news/deprecation-of-sha1-certificates
• https://blog.qualys.com/ssllabs/2014/09/09/sha1-deprecation-what-you-need-to-know

[JaneX8]

@Fyrd, any chance we can implement this too?

[nicdumz]

Note that browsers supporting TLS 1.3 (https://caniuse.com/tls1-3) are likely not accepting SHA1 certs anymore.