Pass ca-certs flag to prometheus-es-exporter binary

Change-Id: Idcf3400c42e8fcbcd474d264c29b3ec34ebc233e
Related-bug: PROD-33577
diff --git a/docker/swarm/stack/monitoring/elasticsearch_exporter.yml b/docker/swarm/stack/monitoring/elasticsearch_exporter.yml
index ce02782..86a1ae6 100644
--- a/docker/swarm/stack/monitoring/elasticsearch_exporter.yml
+++ b/docker/swarm/stack/monitoring/elasticsearch_exporter.yml
@@ -12,7 +12,7 @@
                 encrypted: 1
           service:
             elasticsearch_exporter:
-              command: --es-cluster ${_param:fluentd_elasticsearch_scheme}://${_param:stacklight_log_address}:9200 --nodes-stats-disable --cluster-health-disable --indices-stats-disable
+              command: --es-cluster ${_param:fluentd_elasticsearch_scheme}://${_param:stacklight_log_address}:9200 --nodes-stats-disable --cluster-health-disable --indices-stats-disable --ca-certs /etc/ssl/certs/ca-certificates.crt
               networks:
                 - monitoring
               deploy: