fix meta/salt with missing pillar

Change-Id: I32018e1b1701530ae0369750d54779245f77f693
diff --git a/elasticsearch/meta/salt.yml b/elasticsearch/meta/salt.yml
index bfd5e0f..6cd9b82 100644
--- a/elasticsearch/meta/salt.yml
+++ b/elasticsearch/meta/salt.yml
@@ -1,5 +1,5 @@
 minion:
-  {%- if pillar.elasticsearch.client is defined %}
+  {%- if pillar.get('elasticsearch', {}).get('client') %}
   elasticsearch:
     {%- from "elasticsearch/map.jinja" import client with context %}
     elasticsearch: