location = /robots.txt {
    allow all;
    log_not_found off;
    access_log off;
}

location = /.well-known/carddav {
    return 301 $scheme://$host/remote.php/dav;
}

location = /.well-known/caldav {
    return 301 $scheme://$host/remote.php/dav;
}

location /.well-known/acme-challenge { }