fix meta/salt with missing pillar

Change-Id: I087cf2ddde895746caaaf7fd57125a042803230e
diff --git a/artifactory/meta/salt.yml b/artifactory/meta/salt.yml
index a190b6c..b21c18d 100644
--- a/artifactory/meta/salt.yml
+++ b/artifactory/meta/salt.yml
@@ -1,5 +1,5 @@
 minion:
-  {%- if pillar.artifactory.client is defined %}
+  {%- if pillar.get('artifactory', {}).get('client') %}
   artifactory:
     {%- from "artifactory/map.jinja" import client with context %}
     artifactory: