Collab user with read-write can delete the whole repository

[helmut72]

Describe the bug
Collab user with read-write can delete the whole repository

To Reproduce
Steps to reproduce the behavior:

1. Create a new repository "test" as admin
2. Create a new user "alice" as admin
3. Add user "alice" to repo "test" with read-write permission
4. Change to user "alice" and delete the repo
5. works

Expected behavior
For my understanding, a user with read-write should be able to collab to a repo, but only a user with admin-access to a repo (or a global admin) should be able to delete the whole repository.