Fix etcd migration for HA clusters

cluster/images/etcd/migrate-if-needed.sh

@@ -122,7 +122,6 @@ start_etcd() {
   ${ETCD_CMD} \
     --name="etcd-$(hostname)" \
     --debug \
-    --force-new-cluster \
     --data-dir=${DATA_DIRECTORY} \
     --listen-client-urls http://127.0.0.1:${ETCD_PORT} \
     --advertise-client-urls http://127.0.0.1:${ETCD_PORT} \
@@ -154,7 +153,7 @@ ROLLBACK="${ROLLBACK:-/usr/local/bin/rollback}"
 # If we are upgrading from 2.2.1 and this is the first try for upgrade,
 # do the backup to allow restoring from it in case of failed upgrade.
 BACKUP_DIR="${DATA_DIRECTORY}/migration-backup"
-if [ "${CURRENT_VERSION}" = "2.2.1" -a ! "${CURRENT_VERSION}" != "${TARGET_VERSION}" -a -d "${BACKUP_DIR}" ]; then
+if [ "${CURRENT_VERSION}" = "2.2.1" -a "${CURRENT_VERSION}" != "${TARGET_VERSION}" -a ! -d "${BACKUP_DIR}" ]; then
   echo "Backup etcd before starting migration"
   mkdir ${BACKUP_DIR}
   ETCDCTL_CMD="/usr/local/bin/etcdctl-2.2.1"