restfulizer.js onclick() else clause

[pierlon]

The form still submits when the user cancels the confirmation.

https://github.com/rydurham/Sentinel/blob/master/public/materialize/js/restfulizer.js#L36

Should I make a pull request with the fix?

[rydurham]

I have been meaning to fix this for a while; a pull request would be great!