add missing go_package (#252)
add missing go_package (#252)

Signed-off-by: Sam Xie <c75b57e73b76b04af6c732091deb476a1c5ad58f@gmail.com>
envoyproxy/protoc-gen-validate,envoyproxy/protoc-gen-validate,envoyproxy/protoc-gen-validate,envoyproxy/protoc-gen-validate,envoyproxy/protoc-gen-validate