add more extensions for static files in nginx config

https://bugs.vestacp.com/index.php?do=details&task_id=84

Your can get more extensions from [Wikipedia](http://en.wikipedia.org/wiki/List_of_file_formats)

Now I use this list:
**Images**
jpeg, jpg, png, gif, bmp, ico, svg, tif, tiff
**Web stuff**
css, js, htm, html, ttf, otf, webp, woff
**Documents**
txt, csv, rtf, doc, docx, xls, xlsx, ppt, pptx, odf, odp, ods, odt, pdf
**Adobe**
psd, ai, eot, eps, ps
**Archives**
zip, tar, tgz, gz, rar, bz2, 7z
**Multimedia**
aac, m4a, mp3, mp4, ogg, wav, wma, 3gp, avi, flv, m4v, mkv, mov, mp4, mpeg, mpg, wmv
**Binary**
exe, iso, dmg, swf