Enable Gzip Compression on Nginx

For enabling gzip compression on Nginx it's necessary to edit the file /etc/nginx/nginx.conf, and check if are present and uncommented the following lines:

gzip on;
gzip_disable "msie6";
gzip_vary on;
gzip_proxied any;
gzip_comp_level 6;
gzip_buffers 16 8k;
gzip_http_version 1.1;
gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;