63b22e7026
When you save a metadata field as None, but the value is already None, an error alert is raised in the UI. This is because a metadata key that does not exist is trying to be deleted, so a 404 is returned by the API. This patch catches the 404, and treats it as a success because that indicates that the metadata key isn't associated with the test. Change-Id: Icf5b1c5f726130fc7ff5e5e450d0b137842c7ade