fastcgi_param in server context does not work

[Tomasz Pajor]

When I set fastcgi_param in server context it is not set, if in location 
it is set.
Wiki says it should work in http, server, location context.

server {
    listen 80;
    server_name .landingpage.dev;
    access_log off;
    error_log /var/log/nginx/landingpage.log;

    root /vhosts/landingpage/public;
    charset utf-8;

    fastcgi_index index.php;
    fastcgi_param SITE my_site;

    location / {
        try_files $uri $uri/ @fallback;
        fastcgi_pass unix:/var/run/spawn-fcgi.sock;
        fastcgi_param SCRIPT_FILENAME $document_root/$fastcgi_script_name;
        #fastcgi_param SITE my_site;
        include fastcgi_params;
    }

    location @fallback {
        fastcgi_pass unix:/var/run/spawn-fcgi.sock;
        fastcgi_param SCRIPT_FILENAME $document_root/index.php;
        #fastcgi_param SITE my_site;
        include fastcgi_params;
    }
}