Fix validation on workflow process action in workflow menu

STEPS TO REPRODUCE

First edit document-routing-dashboard-actions-contrib.xml and enable the following actions:

    <action id="workflow_dashboard" link="view_workflow" label="label.main.tab.workflow"
      order="30" enabled="false" type="main_tab">
      <category>MAIN_TABS</category>
    </action>

    <action id="routing_tasks" link="/incl/tabs/workflow_dashboard_tab.xhtml"
      label="action.view.workflow.tasks" order="10" enabled="false">
      <category>WORKFLOW_DASHBOARD</category>
    </action>

Then start your nuxeo instance and:

• Start the 'Parallel document review' default workflow on a File Document.
• Go to Workflow Main tab (Top menu bar)
• Select the listed Task and click 'Process'
• See that the end_date which is required is not required.
• Click on validate

The validation does not apply