CRM-8088 Deleted record still counts as dupe in Event sign-ups

When you sign-up for and event if you are using the same e-mail as a record that has been deleted (but not permanently deleted) you are told you are already sign-up for the event.

To repeat this behavior sign-up here http://drupal.demo.civicrm.org/civicrm/event/register?reset=1&id=3 using the e-mail test3@example.org choosing pay later (unless you want to give $1,000 ) The contact that is signed up using that e-mail is deleted (http://drupal.demo.civicrm.org/civicrm/contact/view?reset=1&cid=276).