title: Cannot use 'null' as class name as it is reserved Concrete 5.7
body: <p>i upgraded my Concrete 5.7 website from php 5.6.x to 7.0.4 and get the folowing error </p>
  
  <pre><code> {"error":{"type":"Whoops\\Exception\\ErrorException","message":"Cannot use 'Null' as class name as it is reserved","file":"\/usr\/share\/nginx\/html\/concrete\/vendor\/zendframework\/zend-queue\/library\/ZendQueue\/Adapter\/Null.php","line":24,"trace":[{"file":"\/usr\/share\/nginx\/html\/concrete\/vendor\/zendframework\/zend-queue\/library\/ZendQueue\/Adapter\/Null.php","line":24,"function":null,"class":null,"args":[]}]},"errors":["Cannot use 'Null' as class name as it is reserved"]}
  </code></pre>
  
  <p>the function that trigger this is a concrete 5 function itself.</p>
  
  <p>What can i do to fix this? </p>
  
  <p>PHP 7.0.12-1+deb.sury.org~trusty+1 (cli) ( NTS )
  Copyright (c) 1997-2016 The PHP Group
  Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies
  with Zend OPcache v7.0.12-1+deb.sury.org~trusty+1, Copyright (c) 1999-2016, by Zend Technologies</p>