If favouriting fails the state of the favourite should not be favourited.
Steps to reproduce (see video with reproducible steps):
- Go to /blue
- Star the hudson pipeline (or a pipeline that has no master to favorite) → you will get an error saying that there is an error starring this pipeline because there is no master. But the pipeline is starred when it shouldn't
- Then star another pipeline successfully. The pipeline before gets unstarred
- Refreshing the screen will show the failed favourite as unfavourited