R1:cdf11c9fd170

Remove unused Phortune exceptions

Summary: These classes are no longer used after D10649.

Test Plan: `grep`

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11168