Issue Summary

If a project's Default Assignee is set to Unassigned the post function "The Assignee of the issue will be set to default." does not unassign the issue, but instead assigns to the project lead.

Steps to Reproduce

1. In a company-managed software project make sure the Default Assignee is Unassigned
2. Create a post function on a transition "The Assignee of the issue will be set to default.":
   
3. Transition an issue
4. Observe that the issue is assigned (I think) to the project lead, not unassigned

Expected Results

The post function should respect the setting of the project's Default Assignee and unassign the issue

Actual Results

The post function assigns the issue to the project lead

Workaround

In the post function set the Field Value to the built-in Unassigned option: