fix error submitting form when no email addresses

also slight change to ensure confirmation page title is tested - instead of just reference number

I looked into it. It will raise an exception saying an email must have a recipient. 

@dan-palmer i thought this too, (3c7b20c70) but couldn't think of an appropriate name, e.g. `send_confirmation_emails` is not right, because it doesn't necessarily do anything. I'm +1 if a sensible method name is found.