pkch: fix copyright

Change-Id: I7fde8a1b4ba123db3413e2a00df520e03d8deffa
Reviewed-on: https://go-review.googlesource.com/48754
Reviewed-by: Jessica Frazelle <me@jessfraz.com>

pkch/main.go

@@ -0,0 +1,10 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("Gopher!!!")
+}