Fix properties usage in ResourceChain update

ResourceChain was using the old properties when trying to build the new
template in updates. Let's rebuild the properties so that it works
properly.

Change-Id: I5ba78995819ec2e1d398a02dad9979575bba05b1
Closes-Bug: #1571638
diff --git a/functional/test_resource_chain.py b/functional/test_resource_chain.py
index c422a26..1086e74 100644
--- a/functional/test_resource_chain.py
+++ b/functional/test_resource_chain.py
@@ -116,6 +116,25 @@
         found = self.list_resources(nested_id)
         self.assertEqual(expected, found)
 
+    def test_update_resources(self):
+        params = {'chain-types': 'OS::Heat::None'}
+
+        stack_id = self.stack_create(template=TEMPLATE_PARAM_DRIVEN,
+                                     parameters=params)
+
+        nested_id = self.group_nested_identifier(stack_id, 'my-chain')
+        expected = {'0': 'OS::Heat::None'}
+        found = self.list_resources(nested_id)
+        self.assertEqual(expected, found)
+
+        params = {'chain-types': 'OS::Heat::None,OS::Heat::None'}
+        self.update_stack(stack_id, template=TEMPLATE_PARAM_DRIVEN,
+                          parameters=params)
+
+        expected = {'0': 'OS::Heat::None', '1': 'OS::Heat::None'}
+        found = self.list_resources(nested_id)
+        self.assertEqual(expected, found)
+
     def test_resources_param_driven(self):
         # Setup
         params = {'chain-types':