Dockerfile: remove the obsolete GO111MODULE env var

Signed-off-by: Raghavendra Talur <[email protected]>

Dockerfile

@@ -18,7 +18,7 @@ COPY main.go main.go
 COPY controllers/ controllers/
 
 # Build
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build -a -o manager main.go
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o manager main.go
 
 FROM registry.access.redhat.com/ubi8/ubi
 WORKDIR /