Having trouble enabling TLSv1.3 on httpd(8)

[Parker Ellertson]

According to my understanding of the manpages (specifically
httpd.conf(5) and tls_config_set_protocols(3)), setting up TLSv1.3
should be just as easy as adding:

        tls {
                protocols "TLS_PROTOCOL_TLSv1_3"
        }

to the appropriate server in /etc/httpd.conf .  But when I do this,
httpd(8) doesn't come up.  Clearly I'm not setting the right variable,
but what is that variable to set?

- Parker