dashboard: use build.golang.org as the domain

The domain returned by appengine.DefaultVersionHostname
isn't the one we want.
This change has been uploaded to build.golang.org

R=golang-dev, rsc, r
CC=golang-dev
https://golang.org/cl/5539043

misc/dashboard/app/build/notify.go

@@ -19,6 +19,7 @@ import (
 const (
 	mailFrom   = "builder@golang.org" // use this for sending any mail
 	failMailTo = "golang-dev@googlegroups.com"
+	domain     = "build.golang.org"
 )
 
 // notifyOnFailure checks whether the supplied Commit or the subsequent
@@ -127,7 +128,7 @@ func sendFailMail(c appengine.Context, com *Commit, builder string) {
 	var body bytes.Buffer
 	err := sendFailMailTmpl.Execute(&body, map[string]interface{}{
 		"Builder": builder, "Commit": com, "Result": r, "Log": l,
-		"Hostname": appengine.DefaultVersionHostname(c),
+		"Hostname": domain,
 	})
 	if err != nil {
 		c.Errorf("rendering mail template: %v", err)

misc/dashboard/app/build/test.go

@@ -146,7 +146,7 @@ func testHandler(w http.ResponseWriter, r *http.Request) {
 			body = new(bytes.Buffer)
 			json.NewEncoder(body).Encode(t.req)
 		}
-		url := "http://" + appengine.DefaultVersionHostname(c) + t.path
+		url := "http://" + domain + t.path
 		if t.vals != nil {
 			url += "?" + t.vals.Encode()
 		}