How to I get rid of "WARN Could not determine content-length of response body

If you get these warning messages in your rails log, just simply put thin to your Gemfile.

WARN  Could not determine content-length of response body. Set content-length of the response or set Response#chunked = true

```ruby Gemfile
gem 'thin'

I found this from this stackoverflow [question](http://stackoverflow.com/questions/7082364/what-does-warn-could-not-determine-content-length-of-response-body-mean-and-h)