Issue: No delete option is available for Multibranch Pipeline project that do not have a indexed branch.

Reproduce:
1. Create a new Multibranch Pipeline.
2. Save empty configuration
3. Go to new Multibranch Pipeline status page.

1. Create a new Multibranch Pipeline.
2. Select a git repository that does not have a Jenkinsfile in any branches.
3. Go to new Multibranch Pipeline status page.

Expectation: Always have the option to delete a Multibranch Pipeline project.