Regenerate all stuff.

examples/appengine/helloworld_standard/proto/helloworld.pb.go

Index: examples/appengine/helloworld_standard/proto/helloworld.pb.go
diff --git a/examples/appengine/helloworld_standard/proto/helloworld.pb.go b/examples/appengine/helloworld_standard/proto/helloworld.pb.go
index 7cf3f4e18280e8cf0647a674b259fc25c470bdf4..bff3ab3053cdc01e0006e7ae4219ed7958d39b90 100644
--- a/examples/appengine/helloworld_standard/proto/helloworld.pb.go
+++ b/examples/appengine/helloworld_standard/proto/helloworld.pb.go
@@ -1,6 +1,5 @@
-// Code generated by protoc-gen-go.
+// Code generated by protoc-gen-go. DO NOT EDIT.
 // source: github.com/luci/luci-go/examples/appengine/helloworld_standard/proto/helloworld.proto
-// DO NOT EDIT!
 
 /*
 Package helloworld is a generated protocol buffer package.
@@ -171,7 +170,7 @@ func init() {
 
 var fileDescriptor0 = []byte{
 	// 190 bytes of a gzipped FileDescriptorProto
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+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x6c, 0x8e, 0x3d, 0xcb, 0xc2, 0x30,
 	0x10, 0xc7, 0x9f, 0xc2, 0x83, 0xd5, 0xc3, 0x29, 0x83, 0x14, 0x27, 0xc9, 0x20, 0x2e, 0x36, 0xa0,
 	0xbb, 0xab, 0xba, 0x56, 0x9c, 0x25, 0x6d, 0x8f, 0xb4, 0x90, 0x37, 0x93, 0x14, 0xed, 0xb7, 0x17,
 	0x83, 0xc5, 0x0e, 0x2e, 0xc7, 0xfd, 0x5f, 0x8e, 0xfb, 0xc1, 0x55, 0xb4, 0xa1, 0xe9, 0xca, 0xbc,