Relocated the site
I've relocated this website to a new server. They old one served well, but it was too beefy and expensive to serve such a small web-site. We used to play Minecraft and I hosted a server for it there, but it's been idle for a long time now.
Instead of a dedicated server (droplet) on DigitalOcean, the site now runs on a smallest shared vCPU server available on Hetzner. Now it costs me only 4.59 EUR a month, instead 12 EUR a month. And I still have place to host my another website and my wife's website.
The other reason for relocation was that I wanted to try Caddy instead of nginx. Caddy promises to be much simpler in operation and provides automatic SSL certificate generation out of the box.
The only things I needed to do after I created a server in Hetzner console were to install Caddy,
put the following lines in its configuration file and restart it with sudo systemctl restart caddy:
dolzhenko.me {
root * /var/www/dolzhenko.me
file_server
}