Fix resolv when all options are not defined

linux/files/resolv.conf

@@ -1,14 +1,14 @@
 {%- from "linux/map.jinja" import network with context %}# Dynamic resolv.conf(5) file for glibc resolver(3) generated by salt-minion(1)
 #     DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
-{% if network.resolv.search -%}
+{% if network.resolv.get('search', False) -%}
 search {{ network.resolv.search|join(' ') }}
 {%- endif %}
-{% if network.resolv.domain -%}
+{% if network.resolv.get('domain' False) -%}
 domain {{ network.resolv.domain }}
 {%- endif %}
 {%- for nameserver in network.resolv.dns %}
 nameserver {{ nameserver }}
 {%- endfor %}
-{%- if network.resolv.options %}
+{%- if network.resolv.get('options', False) %}
 options {{ options|sort|join(' ') }}
 {%- endif %}