Comment 7 for bug 387731

A fix has been cherrypicked into production, so you'll hopefully see
less email from bug-branch links (and unlinks, but that's not a
problem for you I think).

The fix suppresses mail when the bug has no open bug tasks, i.e. any
that are not Invalid, Won't Fix, or Fix Released. I hope that's
enough, but let me know if not (or file another bug).