title: CKEdtior less than sign (<) is not shown after saving
body: <p>I am using a Redmine installation with the CKEditor plugin. We started to document our work in the wiki. One problem is that some commands are not shown correctly after saving. </p>
  
  <p>For example, I write:</p>
  
  <pre><code>mysql -u root -p bitnami_redmine &lt; backup.sql
  </code></pre>
  
  <p>but after saving the page, the less-than sign and everything after it is gone: </p>
  
  <pre><code>mysql -u root -p bitnami_redmine
  </code></pre>
  
  <p>What can I do to correct this behavior?</p>