title: Put a read-only string parameter
body: <p>I am trying to display a parameter on the screen and make it read-only. If I put a string with a default value, the user can change it. Example:</p>
  <pre><code>string(
  name: 'parametro1',
  defaultValue: 'parametro1') 
  </code></pre>
  <p>I have tried to use the following class</p>
  <pre><code>        [$class: 'WReadonlyStringParameterDefinition', 
          name: 'parametro1',
          defaultValue: 'parametro1']
  </code></pre>
  <p>But it shows me the following error</p>
  <p>java.lang.UnsupportedOperationException: no known implementation of class hudson.model.ParameterDefinition is named WReadonlyStringParameterDefinition</p>