issue when un mapped domain goes to existing domain.

• create conf /etc/nginx/sites-available/noserver

server {
    listen 80 default_server;
    listen 443 ssl default_server;
    server_name _;
    ssl_certificate /home/sapan/ssl/nginx-selfsigned.crt;
    ssl_certificate_key /home/sapan/ssl/nginx-selfsigned.key;
    return 444;
}

• link the file to enable it

sudo ln -s /etc/nginx/sites-available/noserver /etc/nginx/sites-enabled/

• generate self signed cert & key

openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout ./nginx-selfsigned.key -out ./nginx-selfsigned.crt