St2: Nginx config error

[codyaray]

The latest Nginx config doesn't work on older nginx versions.

2016/03/22 15:15:57 [emerg] 23052#0: invalid number of arguments in "add_header" directive in /etc/nginx/sites-enabled/st2.conf:47

I'm using Ubuntu 14.04 (LTS) which packages nginx 1.4.6 but the always keyword was added to the nginx add_header directive in 1.7.5.

This bug was introduced as part of a recent change.

I know, I know. I should just open a pull request. :)

/cc @enykeev

[codyaray]

Nginx 1.7.5+ is now a requirement. Since this isn't available in the default Ubuntu repos at the time, I did something like this:

sudo add-apt-repository ppa:nginx/stable
sudo apt-get update
sudo apt-get install nginx

Closing.