Changing Project key, and then navigating it via the top menu leads to a 404. (BB-15806)

Steps to reproduce:

1. Create new Bitbucket project and save settings.
2. Select Projects from top menu, navigate to another (existing) project.
3. Select Projects from top menu, navigate back to the newly created project.
4. Edit the project settings and change the Key.
5. Save the new Key setting for the project.
6. Repeat step 2.
7. Repeat step 3.
8. 404 error.