location /sigmah {
    alias /srv/sigmah;
    try_files $uri @sigmah;
}

location @sigmah {
    proxy_set_header X-Forwarded-For $remote_addr;
    proxy_set_header X-Forwarded-Host $host:$server_port;
    proxy_set_header X-Forwarded-Proto https;
    proxy_pass http://127.0.0.1:9080;
}