Trimmomatic validation passes when steps are absent after clicking "Apply"

Scenario:

1. Open the WD.
2. Add "Read File URL data" and "Improve Reads with Trimmomatic" elements and connect them.
3. Click on the Trimmomatic element, then click on the "Configure steps" parameter in the Property Editor, click on the appeared browse button in the value field.
   Expected state: "Configure Trimmomatic Steps" dialog appears. "Apply" button in the dialog is disabled.
   Current state: the dialog appears, the button is enabled.
4. Close the dialog (in the erroneous scenario click on the enabled "Apply" button, in the GUI test after the fix click on "Cancel").
5. Click "Validate workflow".
   Expected state: Validation doesn't pass, there is an error about absent steps.
   Current state: Validation passes.