Use latest-4.15 channel for release-4.15 branch

Since 4.15 now released better to update the MIRROR and respective
channel accordingly.

snc.sh

@@ -31,7 +31,7 @@ BASE_DOMAIN=${CRC_BASE_DOMAIN:-testing}
 CRC_PV_DIR="/mnt/pv-data"
 SSH="ssh -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -i id_ecdsa_crc"
 SCP="scp -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -i id_ecdsa_crc"
-MIRROR=${MIRROR:-https://mirror.openshift.com/pub/openshift-v4/$ARCH/clients/ocp-dev-preview}
+MIRROR=${MIRROR:-https://mirror.openshift.com/pub/openshift-v4/$ARCH/clients/ocp}
 CERT_ROTATION=${SNC_DISABLE_CERT_ROTATION:-enabled}
 USE_PATCHED_RELEASE_IMAGE=${SNC_USE_PATCHED_RELEASE_IMAGE:-disabled}
 HTPASSWD_FILE='users.htpasswd'
@@ -44,7 +44,7 @@ if test -n "${OPENSHIFT_VERSION-}"; then
     OPENSHIFT_RELEASE_VERSION=${OPENSHIFT_VERSION}
     echo "Using release ${OPENSHIFT_RELEASE_VERSION} from OPENSHIFT_VERSION"
 else
-    OPENSHIFT_RELEASE_VERSION="$(curl -L "${MIRROR}"/candidate-4.15/release.txt | sed -n 's/^ *Version: *//p')"
+    OPENSHIFT_RELEASE_VERSION="$(curl -L "${MIRROR}"/latest-4.15/release.txt | sed -n 's/^ *Version: *//p')"
     if test -n "${OPENSHIFT_RELEASE_VERSION}"; then
         echo "Using release ${OPENSHIFT_RELEASE_VERSION} from the latest mirror"
     else