fix: dev build can set DEV_IMAGE=true (argoproj#2440)

Signed-off-by: Alex Eftimie <[email protected]>

Signed-off-by: Alex Eftimie <[email protected]>

Author: alexef

Makefile

@@ -16,7 +16,7 @@ VERSION=$(shell if [ ! -z "${GIT_TAG}" ] ; then echo "${GIT_TAG}" | sed -e "s/^v
 DOCKER_PUSH=false
 IMAGE_TAG=latest
 # build development images
-DEV_IMAGE=false
+DEV_IMAGE ?= false
 
 # E2E variables
 E2E_INSTANCE_ID ?= argo-rollouts-e2e