Meets #15173:  Subprojects are not copied correctly and the hierarchy is lost

[``* `#15173` Subprojects are not copied correctly and the hierarchy is lost``](https://www.openproject.org/work_packages/15173)
With the stubbing on line 50 this will always be true. I propose adding something like:
expect(User).to_receive(:current).with(user) to the before block to ensure the user to be set correctly. This way you can also remove the after block