match case of workflow var

Dockerfile

@@ -1,12 +1,12 @@
 #first stage - builder
 FROM golang:1.17-alpine as builder
-ARG VERSION
+ARG version 
 RUN apk add build-base
 WORKDIR /app
 COPY . .
 ENV GO111MODULE=auto
 
-RUN GOOS=linux CGO_ENABLED=1 go build -ldflags="-s -X 'main.version=${VERSION}'" -o netmaker main.go
+RUN GOOS=linux CGO_ENABLED=1 go build -ldflags="-s -X 'main.version=${version}'" -o netmaker main.go
 FROM alpine:3.14.3
 
 # add a c lib