Ticket 49540 - Indexing task is reported finished too early regarding the backend status
Bug Description:
If a task complete successfully, its status is updated before the backend
can receive update.
Fix Description:
postpone the task status update after backend is reenabled
https://pagure.io/389-ds-base/issue/49540
Reviewed by: Ludwig Krispenz
Platforms tested: F26
Flag Day: no
Doc impact: no