title: Jenkins Job DSL sshAgent not working correctly
body: <p>For the Jenkins Job DSL, I am trying to choose specific ssh agent (plugin) keys for a job (using the sshAgent keyword inside the wrappers context).  We have the Jenkins ssh agent plugin installed and several keys setup (this plugin works, as we use it for almost all of our jobs).  The Jenkins Job DSL sshAgent command  always picks the first key, regardless of whether I specify a different key in our Jenkins setup.</p>
  
  <p>I have tried using just the key name, but also tried key_name + space + description (just like the dropdowns show).  That does not work either -- still picks the first key.</p>
  
  <p>Is this a known issue?  (I haven't turned up any searches for this yet)</p>