SLA is never stopped when setting resolution/assignee twice

JSD SLA relies on Resolution/Assignee set event which is currently not fired if Workflow has a post-function Set Resolution/Assignee which is affecting our Reporting and SLA in the project.

Steps to reproduce:

1. Configure Workflow and add post-function to set a Resolution/Assignee to the status Done
2. Move issue to the status Done
   Expected results: Resolution even is fired
   Actual result: Resolution is set in DB but even wasn't fired, so SLA is never stopped