Update URLs and paths to new location of the C++ protobuf code.
diff --git a/proto/encode.go b/proto/encode.go
index 026f931..cbe4242 100644
--- a/proto/encode.go
+++ b/proto/encode.go
@@ -950,7 +950,7 @@
var state errorState
// Encode fields in tag order so that decoders may use optimizations
// that depend on the ordering.
- // http://code.google.com/apis/protocolbuffers/docs/encoding.html#order
+ // https://developers.google.com/protocol-buffers/docs/encoding#order
for _, i := range prop.order {
p := prop.Prop[i]
if p.enc != nil {