nginx maintenance configuration error

gistfile1.txt

# This is the relevant configuration block. More can be supplied if needed.
location / {
    try_files /srv/maintenance.html @site;
}

location @site {
    # The site-apache upstream is defined and was working before this. Full config could be supplied if needed.
    proxy_pass http://site-apache/;
}

---

#> service nginx reload
Reloading nginx configuration: [emerg]: "proxy_pass" may not have URI part in location given by regular expression, or inside named location, or inside the "if" statement, or inside the "limit_except" block in /etc/nginx/sites-enabled/site-apache:78
configuration file /etc/nginx/nginx.conf test failed

nginx version: nginx/0.7.65
TLS SNI support enabled
configure arguments: --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --pid-path=/var/run/nginx.pid --lock-path=/var/lock/nginx.lock --http-log-path=/var/log/nginx/access.log --http-client-body-temp-path=/var/lib/nginx/body --http-proxy-temp-path=/var/lib/nginx/proxy --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --with-debug --with-http_stub_status_module --with-http_flv_module --with-http_ssl_module --with-http_dav_module --with-http_gzip_static_module --with-http_realip_module --with-mail --with-mail_ssl_module --with-ipv6 --add-module=/build/buildd/nginx-0.7.65/modules/nginx-upstream-fair