"found in" doesn't take wontfix statuses into account

[gijsk]

https://bugzilla.mozilla.org/show_bug.cgi?id=1300755

has:

(ASSIGNED regression bug found in Firefox 50 which should be worked on in the next release/iteration awaiting an answer on a request for information)

but flags are:

firefox48 --- unaffected
firefox49 --- wontfix
firefox50 --- affected
firefox51 --- affected

so really the bug was found in 49. fix-optional and fixed and verified should probably also affect when we claim the bug was found.