remove lingering KUBE_BUILD_HYPERKUBE

Author: BenTheElder

build/lib/release.sh

@@ -28,7 +28,6 @@ readonly RELEASE_STAGE="${LOCAL_OUTPUT_ROOT}/release-stage"
 readonly RELEASE_TARS="${LOCAL_OUTPUT_ROOT}/release-tars"
 readonly RELEASE_IMAGES="${LOCAL_OUTPUT_ROOT}/release-images"
 
-KUBE_BUILD_HYPERKUBE=${KUBE_BUILD_HYPERKUBE:-y}
 KUBE_BUILD_CONFORMANCE=${KUBE_BUILD_CONFORMANCE:-y}
 KUBE_BUILD_PULL_LATEST_IMAGES=${KUBE_BUILD_PULL_LATEST_IMAGES:-y}