Adapt bgpvpn scenarios to recent sRBAC changes

Change-Id: I7a9a1a7a440cf0b6be28abc877b1d895f69e30c9
Related-Bug: 2019097
diff --git a/neutron_tempest_plugin/bgpvpn/scenario/manager.py b/neutron_tempest_plugin/bgpvpn/scenario/manager.py
index 90c2bb1..2dc8dcf 100644
--- a/neutron_tempest_plugin/bgpvpn/scenario/manager.py
+++ b/neutron_tempest_plugin/bgpvpn/scenario/manager.py
@@ -147,7 +147,7 @@
     def _create_router(self, client=None, tenant_id=None,
                        namestart='router-smoke'):
         if not client:
-            client = self.routers_client
+            client = self.admin_routers_client
         if not tenant_id:
             tenant_id = client.tenant_id
         name = data_utils.rand_name(namestart)