fix missing defined

salt/minion/init.sls

@@ -1,7 +1,7 @@
 include:
 - salt.minion.service
 - salt.minion.grains
-{%- if pillar.salt.minion.graph_states %}
+{%- if pillar.salt.minion.graph_states is defined %}
 - salt.minion.graph
 {%- endif %}
 {%- if pillar.salt.minion.ca is defined %}