vcs-test/vcweb: add Autocert notification email

Add golang-dev as the Autocert notification email so Let's Encrypt can
send us emails. golang-dev is not an ideal choice, but we need something
publicly accessible and there isn't an obvious better option. My
understanding is we should expect essentially no emails so I don't want
to worry too much about it.

Updates golang/go#47108.

Change-Id: I22951984e0d48a59787d110b9cef32cbe3d9bc4a
Reviewed-on: https://go-review.googlesource.com/c/build/+/334532
Trust: Heschi Kreinick <heschi@google.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/vcs-test/vcweb/main.go b/vcs-test/vcweb/main.go
index 0d5f84c..58be954 100644
--- a/vcs-test/vcweb/main.go
+++ b/vcs-test/vcweb/main.go
@@ -90,6 +90,7 @@
 			Cache:      autocertcache.NewGoogleCloudStorageCache(client, "vcs-test-autocert"),
 			Prompt:     autocert.AcceptTOS,
 			HostPolicy: autocert.HostWhitelist("vcs-test.golang.org"),
+			Email:      "golang-dev@googlegroups.com", // for lack of a better choice.
 		}
 		s := &http.Server{
 			Addr:    ":https",