Backup Service - Plan deletion warning fails on Safari

Description:

On Safari, a user can enter an arbitrary plan name or no plan name and hit the return key to delete a plan.

Steps to reproduce:

1. Using Safari, create a plan with a specific plan name.
2. Hit the delete button.
3. Enter an arbitrary plan name or no plan name and hit return.

What happens:

The plan is deleted.

What I expected to happen:

I expected the plan to deleted only when its name is entered correctly.