remove fail2ban nginx-dos.conf because it doesn't work properly
http://serverfault.com/questions/420895/how-to-use-fail2ban-for-nginx
it bans users when they aren't even close to the rate limit, such as
when one simply uses phpMyAdmin
the proper way to do this is through nginx itself via http_limit_req
http://snippets.aktagon.com/snippets/554-how-to-secure-an-nginx-server-with-fail2ban
http://nginx.org/en/docs/http/ngx_http_limit_req_module.html