title: How to make 'Auto Complete String Parameter' required mandatory in Jenkins Pipeline?
body: <p>For Jenkins Pipeline, I've a 'Auto Complete String Parameter' where in user types in text and matching options are listed.</p>
  <p>But as it is not required parameter, sometime user enter no value and proceed with build and hence it fails after build is started.</p>
  <p>To avoid this, is there a way to mark 'Auto Complete String Parameter' as required parameter so if value for it is not provided, build will not be started.</p>