fix meta/salt with missing pillar

Change-Id: Ie20651fb661603211e6ed289dd5aff9002740548
diff --git a/jenkins/meta/salt.yml b/jenkins/meta/salt.yml
index bd821ec..b46fdb5 100644
--- a/jenkins/meta/salt.yml
+++ b/jenkins/meta/salt.yml
@@ -1,5 +1,5 @@
 minion:
-  {%- if pillar.jenkins.client is defined %}
+  {%- if pillar.get('jenkins', {}).get('client') %}
   jenkins:
     {%- from "jenkins/map.jinja" import client with context %}
     jenkins: