[Transverse] Milestone missing in folder campaign deletion process
**Affected version : 5.1 & 7.0.0**
**Steps to reproduce**
Have a milestone associates to a project and so, at campaign and objects (folder, campaign, iteration...)
Have a folder in Campaign workspace of this project, and severals campaign into.
Try to delete this folder
**observed behavior**
Folder can't delete
**Expeted result**
Folder can be delete
issue