title: Unable to see launch slave agents on Unix machines via SSH on Jenkins
body: <p>I have two different Jenkins instances with different versions.
  One has version 1.609.1 and when I create a slave on it I see options in the launch method like:</p>
  
  <ul>
  <li><em>"Launch slaves agents on a Unix machine via SSH"</em></li>
  <li><em>"Launch slave agents via Java web start"</em></li>
  <li><em>"Launch slaves via execution of command on the master and let Jenkins control this Windows slave as a Windows service"</em></li>
  </ul>
  
  <p>I have one more instance that is of version 2.89.4, but the slave launch option is different - it has one *"Launch slaves agent via SSH". The rest of the all options are the same.</p>
  
  <p>Is this slave launching option something version-specific?</p>