nginx_server_name config options

[vedant1811]

The nginx_server_name config works as specified apparently but there are downsides to it.

If I do not set anything, it defaults to the IP used to deploy. This may be undesirable (was for me). I wanted this field to be not set altogether so that my app replies to server IP, mydomain.com, www.mydomain.com and also the EC2 domain. This behaviour actually broke my production app; I did not encounter this problem in staging as I was using the IP itself in the browser.

Also, I was unable to set it to multiple values, like:
set :nginx_server_name, 'mydomain.com www.mydomain.com'

Not setting it and/or setting multiple values may be out of convention but seems like a desirable feature. Even if you don't add it, reflect this behaviour in the docs. Regards.

[rhomeister]

Happy to accept a PR for this!