Updating local proto copy to work the same on osx and linux(tested on ubuntu)

Change-Id: Iab40e72250e5c507347a594bcda6f1f34f689933
diff --git a/Makefile b/Makefile
index 257d372..cc5e34e 100644
--- a/Makefile
+++ b/Makefile
@@ -86,7 +86,7 @@
 base:
 ifdef LOCAL_PROTOS
 	mkdir -p vendor/github.com/opencord/voltha-protos/go
-	cp -r ${GOPATH}/src/github.com/opencord/voltha-protos/go/ vendor/github.com/opencord/voltha-protos
+	cp -r ${GOPATH}/src/github.com/opencord/voltha-protos/go/* vendor/github.com/opencord/voltha-protos/go
 endif
 	docker build $(DOCKER_BUILD_ARGS) -t base:latest -f docker/Dockerfile.base .