protoc-gen-go: fix release tag in golden_test (#590)
protoc-gen-go: fix release tag in golden_test (#590)

The 1.9 release tag is "go1.9", not "1.9".
golang/protobuf,fuchsia-mirror/third_party-github.com-golang-protobuf,golang/protobuf,fuchsia-mirror/third_party-github.com-golang-protobuf