Change getting public net from pillar

Change-Id: If1d01d37f3929db7366edfab27dbf182543f0769
diff --git a/_modules/runtest/tempest_sections/network.py b/_modules/runtest/tempest_sections/network.py
index 68d4fea..d12a871 100644
--- a/_modules/runtest/tempest_sections/network.py
+++ b/_modules/runtest/tempest_sections/network.py
@@ -84,8 +84,10 @@
         c = conditions.BaseRule(field='keystone.client.enabled', op='eq',
                                 val=True)
         nodes = self.get_nodes_where_condition_match(c)
-        network_name = self.runtest_opts.get(
-            'convert_to_uuid', {}).get('public_network_id')
+        runtest_enable = conditions.BaseRule('runtest.enabled', 'eq', True)
+        network_name = self.get_item_when_condition_match(
+            'runtest.tempest.convert_to_uuid.network.public_network_id',
+            runtest_enable)
 
         if not network_name:
           return