title: Can't fill in Project Key for quality gates plugin
body: <p>I'm trying to user Sonarqube with Jenkins.</p>
  
  <p>I've added the Quality Gates Plugin, to fail the build in Jenkins if the Quality Gates are not respected in Sonarqube.</p>
  
  <p>However, as you can see below, there is no <strong>Project Key</strong> field for Quality Gates.</p>
  
  <p><a href="https://i.stack.imgur.com/j2AF9.png" rel="noreferrer"><img src="https://i.stack.imgur.com/j2AF9.png" alt="enter image description here"></a></p>
  
  <p>Also, if I try to save the configuration, I get:</p>
  
  <pre><code>JSONObject["projectKey"] not found.
  </code></pre>
  
  <p>Any idea why this would not appear?</p>