Merge pull request #333 from openshift-bot/art-consistency-openshift-…

…4.8-prom-label-proxy

Updating prom-label-proxy builder & base images to be consistent with ART

Dockerfile.ocp

@@ -1,5 +1,5 @@
 # FROM directives are overriden by CI system (both Prow CI and OSBS)
-FROM registry.ci.openshift.org/ocp/builder:rhel-8-golang-1.15-openshift-4.8 AS builder
+FROM registry.ci.openshift.org/ocp/builder:rhel-8-golang-1.16-openshift-4.8 AS builder
 
 WORKDIR /go/src/github.com/openshift/prom-label-proxy
 COPY . .