Deleting a parent category makes its children become parents instead of deleting them

[rowasc]

Describe the bug
When I click on "delete" for a category with children, I expect the child categories to be deleted. Instead, the child categories appear to become parents.

Where was the bug observed
https://rominacsvsms.ushahidi.io/
https://isooko-stg.ushahidi.com

To Reproduce
Steps to reproduce the behavior:

1. Go to Settings->Categories (I tried this logged in as admin)
2. Create a parent category
3. Add a child to the parent category you created
4. Go to the categories list
5. Delete the parent category
6. The child category will become a parent.

Expected behavior
5. The child category will be deleted

Is there a workaround? What is it.
Select all the children of the parent category and delete them

Desktop Hardware Details (please complete the following information):

• OS: Mac OS
• Browser: Chrome
• Version: 68.0.3440.106

Aha! Link: https://ushahiditeam.aha.io/features/PROD-303

[rowasc]

@jrtricafort found this today. Assigning to you for prioritization

[e-stephane]

Hello @rowasc @Angamanga, i will like to start working on this issue.

[rowasc]

@e-stephane awesome, thank you ! Looking forward to your contributions!

[helen-ndip]

@rowasc @Angamanga is this issue still available to work on? I would like to take on it, I see its still open.

[renujain31]

Hey can I work on this? @rowasc @Angamanga

[rowasc]

@helen-ndip you can, altough it's likely this involves backend development (and debugging) as well, is that okay?
If yes, go ahead and I'll assign it.

[helen-ndip]

@helen-ndip you can, altough it's likely this involves backend development (and debugging) as well, is that okay?
If yes, go ahead and I'll assign it.

Thanks I will.

[Angamanga]

Removing community-task label since the behaviour is clearly specified and decided on yet