Enable fluentd health check

This patch enables container health check for fluentd container.

Change-Id: I2d8f04c0dd806b2e39a38f8b9e96f50c1e0f75e0
Depends-On: Ie724b155fa071da9f1baee193cf79e2ecdc2ff30

docker/services/fluentd.yaml

@@ -90,6 +90,8 @@ outputs:
             privileged: true
             user: root
             restart: always
+            healthcheck:
+              test: /openstack/healthcheck
             volumes:
               list_concat:
                 - {get_attr: [ContainersCommon, volumes]}