title: Talend: Update global variable in subjob
body: <p>My simplified job look like this:</p>
  
  <p>tSetGlobalVar--->(onSubJobOK)--->tRunJob--->(onSubJobOK)--->tJava</p>
  
  <ul>
  <li>tSetGlobalVar will define a global variable and its initial value let's say: <code>myKey:"firstValue"</code></li>
  <li>tRunJob will run a sub job which contain only a second tSetGlobalVar component that's supposed to set a new value to the global variable defined in the master job:
  <code>((String)globalMap.get("myKey")): "newValue"</code>
  also tried this: 
  <code>"myKey": "newValue"</code></li>
  <li>tJava used just to debug, it's code is like below:
  <code>System.out.println(((String)globalMap.get("myKey")));</code></li>
  </ul>
  
  <p>Actual output: <code>firstValue</code></p>
  
  <p>Expected output: <code>newValue</code></p>
  
  <p>Is there any other way to modify the value of a global variable in a subjob and get the updated value in the master job ?</p>