When checking if a bug is closed we go through all of its affecting
project statuses, and if a status is Won't Fix the bug will stay on the
recheckwatch list. But if a bug is marked as won't fix its safe to
assume the root cause of the issue is fixed. Otherwise the bug will
happen again and someone will set the status back to open.
For example: https://bugs.launchpad.net/nova/+bug/1186867
Change-Id: Iaddc4990062d5a80e188f10c14e91625b7605165
1686cbb009