Fix, group members

Change-Id: I71c2dd4b1970b39427beda6465b7a4726b12897b

linux/system/group.sls

 
 {%- if group.enabled %}
 
+{%- set requires = [] %}
+{%- for user in group.get('addusers', []) %}
+  {%- if user in system.get('user', {}).keys() %}
+    {%- do requires.append({'user': 'system_user_'+user}) %}
+  {%- endif %}
+{%- endfor %}
+
 system_group_{{ group_name }}:
   group.present:
   - name: {{ group.get('name', group_name) }}
   {%- if group.gid is defined and group.gid %}
   - gid: {{ group.gid }}
   {%- endif %}
+  - require: {{ requires|yaml }}
 {{ set_p('addusers', group)|indent(2, True) }}
 {{ set_p('delusers', group)|indent(2, True) }}
 

tests/pillar/system.sls

         enabled: true
         delusers:
           - salt_user1
+          - dontexistatall
       salt-ops:
         enabled: true
         name: salt-ops