title: Django SuspiciousOperation after upgrade to 1.10
body: <p>Recently I have upgraded my apps from 1.8 to 1.10 and now I get flooded by this error:</p>
  
  <p>Exception Type: SuspiciousOperation at &lt;&lt; VARIOUS_PAGES >></p>
  
  <p>Exception Value: The request's session was deleted before the request completed. The user may have logged out in a concurrent request, for example.</p>
  
  <p>I can't figure out why this happen but it seems that the session expires prematurely for some strange reason.</p>