==== REQUIRED BASIC INFO OF YOUR IREDMAIL SERVER ====
- iRedMail version (check /etc/iredmail-release): 1.5.2
- Deployed with iRedMail Easy or the downloadable installer? yes
- Linux/BSD distribution name and version:  centos 8
- Store mail accounts in which backend (LDAP/MySQL/PGSQL):  mysql
- Web server (Apache or Nginx): nginx
- Manage mail accounts with iRedAdmin-Pro? no
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====
When I enable roundcube-subdomain.tmpl
I get this error and can not start nginx
2022/05/03 12:51:25 [emerg] 95040#0: duplicate location "/" in /etc/nginx/templates/roundcube-subdomain.tmpl:16
here is roundcube-subdomain.tmpl

#
# Run Roundcube as a sub-domain virtual host.
#
# Block access to default directories and files under these directories
location ~ ^/(bin|config|installer|logs|SQL|temp|vendor)/.* { deny all; }

# Block access to default files under top-directory and files start with same name.
location ~ ^/(CHANGELOG|composer.json|INSTALL|jsdeps.json|LICENSE|README|UPGRADING)$ { deny all; }

# Block plugin config files and sample config files.
location ~ ^/plugins/.*/config.inc.php.* { deny all; }

# Block access to plugin data
location ~ ^/plugins/enigma/home($|/.*) { deny all; }

location / {
    root    /opt/www/roundcubemail;
    index   index.php index.html;
    include /etc/nginx/templates/hsts.tmpl;
}

location ~ \.php$ {
    root /opt/www/roundcubemail;
    include /etc/nginx/templates/fastcgi_php.tmpl;
    fastcgi_param SCRIPT_FILENAME /opt/www/roundcubemail$fastcgi_script_name;
}