/etc/nginx/sites-available/portal-nginx.conf is in liblemonldap-ng-portal-perl 1.9.16-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /etc/nginx/sites-available/../../lemonldap-ng/portal-nginx.conf
/etc/nginx/sites-available/../../lemonldap-ng/portal-nginx.conf