Do not override DAEMON_ARGS through /etc/default files
After adding support we faced broken configuration for openstack
services (see related bug). OS services' init.d files "sources"
/etc/defaults/{service_name} files which could override DAEMON_ARGS.
Change-Id: Ie8f8bc121be7425c06357765ccc0d33fd8001ac9
Related-bug: PROD-17968
diff --git a/nova/files/default b/nova/files/default
index 815ede9..be934df 100644
--- a/nova/files/default
+++ b/nova/files/default
@@ -1,4 +1,4 @@
# Generated by Salt.
{% if values.logging.log_appender %}
-DAEMON_ARGS="--log-config-append=/etc/nova/logging/logging-{{ service_name }}.conf"
+DAEMON_ARGS="${DAEMON_ARGS} --log-config-append=/etc/nova/logging/logging-{{ service_name }}.conf"
{% endif %}