fix a bug that miss builds when the last verdict is good

see https://bugzilla.mozilla.org/show_bug.cgi?id=1111340
Merge pull request #149 from parkouss/fix_hunting_regression

fix a bug that miss builds when the last verdict is good
Improve nightly hunting speed for mozregression

See https://bugzilla.mozilla.org/show_bug.cgi?id=1111185