title: No answer from Facebook chat when connecting through XMPP
body: <p>I'm using node-xmpp to connect to Facebook chat XMPP api.
  I cannot find why, but sometimes everything is fine : I ask facebook for a connection with my ID (-@chat.facebook.com), my api_key, my access_token and the host (chat.facebook.com), and it answers me an online notification followed by presence messages.
  But sometimes (many times in fact), I just don't have any answer from Facebook whereas I send the exact same request...</p>
  
  <p>Have you ever experienced similar issues with Facebook?
  Do you guys have an idea on what's going on?</p>
  
  <p>Thanks a lot</p>
  
  <p>S.</p>