ironic: remove notifier_strategy option

This has never exited in Ironic, and it does not even uses notification.

Change-Id: I4a3d386116561d9a22d650f123df1aae5ed9849e
diff --git a/lib/ironic b/lib/ironic
index b8838f5..983add8 100644
--- a/lib/ironic
+++ b/lib/ironic
@@ -105,11 +105,6 @@
     iniset $IRONIC_CONF_FILE keystone_authtoken admin_tenant_name $SERVICE_TENANT_NAME
     iniset $IRONIC_CONF_FILE keystone_authtoken admin_user ironic
     iniset $IRONIC_CONF_FILE keystone_authtoken admin_password $SERVICE_PASSWORD
-    if is_service_enabled qpid; then
-        iniset $IRONIC_CONF_FILE DEFAULT notifier_strategy qpid
-    elif [ -n "$RABBIT_HOST" ] &&  [ -n "$RABBIT_PASSWORD" ]; then
-        iniset $IRONIC_CONF_FILE DEFAULT notifier_strategy rabbit
-    fi
     iniset_rpc_backend ironic $IRONIC_CONF_FILE DEFAULT
     iniset $IRONIC_CONF_FILE keystone_authtoken signing_dir $IRONIC_AUTH_CACHE_DIR/api