title: XMPPFramework does not send keep alive in background even with enableBackgroundingOnSocket set to TRUE
body: <p>I think the title is illustrating enough. I want <code>XMPPFramework</code> to work ( like a service ) in background and receive messages even when app is not in active state. I have set</p>
  
  <p><code>xmppStream.enableBackgroundingOnSocket = YES;</code></p>
  
  <p>But no progress here.
  The app goes to background, it still receives messages ( and shows notifications ) for a few seconds, but if it be inactive for a few seconds ( and idle also ( no incoming message ) ) it would no longer work in the background.
  I have trying logging and saw that the app is sending keep-alive packets, within a few seconds after receiving last message ( last activity ) , but if there be no activity for a few time, it stops sending keep-alives and the app wouldn't be notified and work anymore.
  Just in case it matters, I have set "keep alive sending interval" to 5 seconds.</p>
  
  <p>I really appreciate any quick help.</p>
  
  <p>Thanks a lot</p>