title: unable to delete __ci_last_regenerate from session
body: <p>This <code>__ci_last_regenerate</code> is screwing my session. Is there a way of removing this from session array ?</p>
  
  <p>When i set session for user and i print session, the session array is created correctly but its is proceeded by <code>__ci_last_regenerate</code>. Also when i destroy session the session array has only one element and its that bloody <code>__ci_last_regenerate</code>. </p>
  
  <p>Session after login :</p>
  
  <pre><code>array(2) { 
        ["__ci_last_regenerate"]=&gt; int(1475532963) 
        ["cb7a1d775e800fd1ee4049f7dca9e041eb9ba083"]=&gt; array(2) { 
                ["id"]=&gt; string(2) "37" 
                ["email"]=&gt; string(19) "admin@admin.com" 
        } 
  }
  </code></pre>
  
  <p>Session after logout (when calling session destroy)</p>
  
  <pre><code>array(1) { 
         ["__ci_last_regenerate"]=&gt; int(1475533350) 
  }
  </code></pre>