Set the default preferred docker image to golang

DOCKER_TAG-py and DOCKER_TAG-go are still set.
The base DOCKER_TAG is now the golang version

Change-Id: Ib6846964ebd7283def9716c7e806f9e9c3825c22
diff --git a/Makefile b/Makefile
index b3fd408..81f09f3 100644
--- a/Makefile
+++ b/Makefile
@@ -129,7 +129,7 @@
 	docker build $(DOCKER_BUILD_ARGS_LOCAL) -t ${PYTHONADAPTER_IMAGENAME} -f python/docker/Dockerfile.openolt_adapter python
 
 	# Current default image gets the base DOCKER_TAG
-	docker tag ${PYTHONADAPTER_IMAGENAME} ${ADAPTER_IMAGENAME}
+	docker tag ${GOADAPTER_IMAGENAME} ${ADAPTER_IMAGENAME}
 
 docker-push:
 	docker push ${GOADAPTER_IMAGENAME}