Job Variables with "Empty String" value are displayed as "Undefined" in the variable's text box

[luispinedamx]

When a Job Variable is defined with an empty string as value, the text box in the studio displays the text "undefined", which can be confusing for the user; especially because this behavior does not happen with Task Variables.

Steps to reproduce:

1. Create a workflow
2. Add a Job Variable (say "var1") to it. Leave the "value" box empty to indicate that its value is an empty string.
3. Click OK
4. The value text box of the variable displays "Undefined".