title: get the username of who triggered pipeline job ( manually or scm trigger)
body: <p>I have a job that gets built in two ways :</p>
  
  <ol>
  <li>IF someone commits to the github repo , triggering the job.</li>
  <li>IF someone manually builds the job. </li>
  </ol>
  
  <p>within my pipeline, I need to get the name/info of person who triggered the build either directly (manually) or indirectly(SCM commit). I have the following code:</p>
  
  <pre><code>node('slave'){
      wrap([$class: 'BuildUser']) {
        return BUILD_USER
      }
  } 
  </code></pre>
  
  <p>This gets me the name using the <a href="https://wiki.jenkins-ci.org/display/JENKINS/Build+User+Vars+Plugin" rel="nofollow noreferrer">https://wiki.jenkins-ci.org/display/JENKINS/Build+User+Vars+Plugin</a> plugin. </p>
  
  <p><strong>This works on manual but always gives SCM trigger when through SCM trigger. How do I get the name/info of the person who committed for the trigger to happen via SCM ?</strong></p>