title: iPhone5 migration: black bar between tabbar and content view
body: <p>I try to migrate an app to iPhone5/iOS6.
  I have already successfully migrated some apps with basic recommandation (-568h@2x).</p>
  
  <p>BUT for this app, a black bar appears between the bottom toolbar and the middle of the screen (Cf. attached image).</p>
  
  <p><img src="https://i.stack.imgur.com/YYrqP.png" alt="black bar"></p>
  
  <p>Normally, the black bar should be filled with the tableview...</p>
  
  <p>Of course, I have correctly set the tableview constraint in Interface Builder...</p>