Merge pull request #103 from joonas/set-goproxy-to-default-if-empty

Set GOPROXY to default if it is not configured

Author: k8s-ci-robot

Makefile

@@ -14,7 +14,9 @@
 
 # Use GOPROXY environment variable if set
 GOPROXY := $(shell go env GOPROXY)
-GOPROXY ?= https://proxy.golang.org
+ifeq ($(GOPROXY),)
+GOPROXY := https://proxy.golang.org
+endif
 export GOPROXY
 
 REGISTRY ?= gcr.io/$(shell gcloud config get-value project)