Fixing TLS1.3 support in nginx

Hi, I would like to fix bug in the nginx configuration. I created a merge request !1364 (merged)

In the original code, this part of code $output = $app->system->exec_safe('nginx -V 2>&1'); return the last line from the result of the command:

configure arguments: --prefix=/usr/share/nginx --sbin-path=/usr/sbin/nginx --modules-path=/usr/l... Correct information is in second or third line by distribution:

built with OpenSSL 1.1.1g....

But in "system" exist function getopensslversion that returns open ssl version from command openssl version.

If the version from openssl version is not sufficient, than i can check all lines from nginx -V 2>&1.

And second problem was in $vhost_data key tls1.3_supported, key cannot contain dot, as you can see in tpl.inc.php on line 327 /^[A-Za-z_]+[A-Za-z0-9_]*$/