KeyPairsClient: Configure client to query nova service from Keystone catalog

Change-Id: Ibf2fe805a92d178de0792bb42c2cd3df721c625e
diff --git a/tempest/services/nova/json/keypairs_client.py b/tempest/services/nova/json/keypairs_client.py
index 7c29215..73b92a9 100644
--- a/tempest/services/nova/json/keypairs_client.py
+++ b/tempest/services/nova/json/keypairs_client.py
@@ -7,7 +7,7 @@
     def __init__(self, config, username, key, auth_url, tenant_name=None):
         self.config = config
         self.client = rest_client.RestClient(config, username, key,
-                                             auth_url, tenant_name)
+                                             auth_url, 'nova', tenant_name)
         self.headers = {'Content-Type': 'application/json',
                         'Accept': 'application/json'}