NO-ISSUE: revert unwanted images mirroring (#1694)

* revert unwanted images mirroring

* restore original checks to allow  setting OPENSHIFT_INSTALL_RELEASE_IMAGE_OVERRIDE when required

Author: andfasano

common.sh

@@ -73,10 +73,6 @@ export SSH_PUB_KEY="${SSH_PUB_KEY:-$(cat $HOME/.ssh/id_rsa.pub)}"
 
 # mirror images for installation in restricted network
 export MIRROR_IMAGES=${MIRROR_IMAGES:-}
-# For IPv6 (default case) mirror images are used since quay doesn't support IPv6
-if [[ -z "${IP_STACK:-}" || "$IP_STACK" = "v6" || "$IP_STACK" = "v6v4" ]]; then
-    export MIRROR_IMAGES=${MIRROR_IMAGES:-true}
-fi
 
 # identify the command used to mirror images, either 'oc-adm' or 'oc-mirror'
 export MIRROR_COMMAND=${MIRROR_COMMAND:-oc-adm}
@@ -485,7 +481,7 @@ if [[ ! -z ${AGENT_E2E_TEST_BOOT_MODE} ]]; then
   esac
 fi
 
-if [[ -n "$MIRROR_IMAGES" && "${MIRROR_IMAGES,,}" != "false" ]]; then
+if [[ (-n "$MIRROR_IMAGES" && "${MIRROR_IMAGES,,}" != "false") || -z "${IP_STACK:-}" || "$IP_STACK" = "v6" ]]; then
 
    if [[ "${MIRROR_COMMAND}" == "oc-mirror" ]]; then
       # Use the string that is generated by the output of oc-mirror