[Cdash] No email on failed continuous builds

[Trevor Kellaway]

Hi,

BTW, previously with email notification set to "Email me when checkins
are breaking nightly dashboard" emails were incorrectly being sent when
Experimental builds were failing (for other users), I'll check if this
is still happening now I'm at r985.

Later: Hmm, this bug still appears to be present, when I submitted a
failing Experimental (I can't test as another user). Surely this
shouldn't be happening?

 -Trevor