Umm, for the above test I forgot then restart apache2 and see if it complains:
good: (no message, server starts)
bad: Sep 25 08:12:21 b apachectl[16488]: AH00526: Syntax error on line 73 of /etc/apache2/mods-enabled/ssl.conf: Sep 25 08:12:21 b apachectl[16488]: SSLProtocol: Illegal protocol 'TLSv1.3' Sep 25 08:12:21 b apachectl[16488]: Action 'start' failed.
Umm, for the above test I forgot then restart apache2 and see if it complains:
good: (no message, server starts)
bad: mods-enabled/ ssl.conf:
Sep 25 08:12:21 b apachectl[16488]: AH00526: Syntax error on line 73 of /etc/apache2/
Sep 25 08:12:21 b apachectl[16488]: SSLProtocol: Illegal protocol 'TLSv1.3'
Sep 25 08:12:21 b apachectl[16488]: Action 'start' failed.