Make security group description optional in the client.sls

Related prod: PROD-11917

Change-Id: Iebc4f7d095cee2238bc181bf94bb954737a760cc
diff --git a/_states/neutronng.py b/_states/neutronng.py
index 89e0011..afca39b 100644
--- a/_states/neutronng.py
+++ b/_states/neutronng.py
@@ -409,7 +409,7 @@
 
 def security_group_present(name=None,
                            tenant=None,
-                           description=None,
+                           description='',
                            rules=[],
                            profile=None,
                            endpoint_type=None):
diff --git a/neutron/client.sls b/neutron/client.sls
index e31e969..0976115 100644
--- a/neutron/client.sls
+++ b/neutron/client.sls
@@ -108,7 +108,9 @@
 openstack_security_group_{{ security_group_name }}:
   neutronng.security_group_present:
     - name: {{ security_group_name }}
+    {%- if security_group.description is defined %}
     - description: {{ security_group.description }}
+    {%- endif %}
     - rules: {{ security_group.rules }}
     - profile: {{ identity_name }}
     - tenant: {{ security_group.tenant }}