dashboard/app: fix the broke-the-build commit URL

Change-Id: I153211b2609b18210227f0cd805bd4b52df83ecb
Reviewed-on: https://go-review.googlesource.com/2056
Reviewed-by: Andrew Gerrand <adg@golang.org>

Author: bradfitz

dashboard/app/build/notify.txt

@@ -3,7 +3,7 @@ http://{{.Hostname}}/log/{{.LogHash}}
 
 {{.Commit.Desc}}
 
-http://code.google.com/p/go/source/detail?r={{shortHash .Commit.Hash}}
+https://golang.org/change/{{shortHash .Commit.Hash}}
 
 $ tail -200 < log
 {{printf "%s" .LogText | tail 200}}