Add link to ctpixeldiff.skia.org in pixel diff completion email
Add link to ctpixeldiff.skia.org in pixel diff completion email

Bug: skia:6944
Change-Id: I408124b6aa315ed63a3221ce50064634c6b43f77
Reviewed-on: https://skia-review.googlesource.com/32680
Reviewed-by: Ben Wagner <3ef7217be91069877d94f7907ce5479000772cd3@google.com>
Commit-Queue: Ravi Mistry <9fa2e7438b8cb730f96b74865492597170561628@google.com>

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot