title: Why do I get this error `Errno::ECONNREFUSED (Connection refused - connect(2))`?
body: <p>I'm using devise and reCaptcha.<br>
  Right after I signed up, <code>Something went wrong</code> error occured.<br>
  So I took a look at log. it says this.</p>
  
  <pre><code>Completed 500 Internal Server Error in 1366ms
  
  Errno::ECONNREFUSED (Connection refused - connect(2)):
    app/controllers/registrations_controller.rb:6:in `create'
  </code></pre>
  
  <p>Everything was working perfectly in development mode, then why I'm getting this in production mode?</p>
  
  <p><strong>registrations_controller.rb</strong></p>
  
  <pre><code>4. def create
  5.     if verify_recaptcha
  6.         super
  7.         flash.delete(:recaptcha_error)
  8.         else
  </code></pre>