doc/play: update URL for concurrent pi

The old link died; replace with an archive.org copy.

Fixes #13345.

Change-Id: Ic4a7fdcf258e1ff3b4a02ecb4f237ae7db2686c7
Reviewed-on: https://go-review.googlesource.com/18335
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/doc/play/pi.go b/doc/play/pi.go
index f2f5dca748f5163f2ec14b3ff98bb3c346b48dec..f61884e888dafde44802d42edb5fb13e8707f07c 100644 (file)
--- a/doc/play/pi.go
+++ b/doc/play/pi.go
@@ -1,5 +1,5 @@
 // Concurrent computation of pi.
-// See http://goo.gl/ZuTZM.
+// See https://goo.gl/la6Kli.
 //
 // This demonstrates Go's ability to handle
 // large numbers of concurrent processes.