Fix cleanup CLI for router client

neutron router client is splitted out into separate class.

Fix cleanup CLI for the same.

Change-Id: Ie4ddf88f058d214d49a5797a40255005445c67df
diff --git a/tempest/cmd/cleanup_service.py b/tempest/cmd/cleanup_service.py
index 28ffb56..a0676b6 100644
--- a/tempest/cmd/cleanup_service.py
+++ b/tempest/cmd/cleanup_service.py
@@ -390,6 +390,7 @@
         self.metering_labels_client = manager.metering_labels_client
         self.metering_label_rules_client = manager.metering_label_rules_client
         self.security_groups_client = manager.security_groups_client
+        self.routers_client = manager.routers_client
 
     def _filter_by_conf_networks(self, item_list):
         if not item_list or not all(('network_id' in i for i in item_list)):