Fix tempest removing variables

Change-Id: Id014e6b0d1d65b8bac4c1b7e6becd4a972913f6b
diff --git a/designate_tempest_plugin/clients.py b/designate_tempest_plugin/clients.py
index 5a8136c..87b43c4 100644
--- a/designate_tempest_plugin/clients.py
+++ b/designate_tempest_plugin/clients.py
@@ -53,8 +53,8 @@
 
 class ManagerV1(clients.Manager):
 
-    def __init__(self, credentials=None, service=None):
-        super(ManagerV1, self).__init__(credentials, service)
+    def __init__(self, credentials=None):
+        super(ManagerV1, self).__init__(credentials)
         self._init_clients(self._get_params())
 
     def _init_clients(self, params):
@@ -77,8 +77,8 @@
 
 class ManagerV2(clients.Manager):
 
-    def __init__(self, credentials=None, service=None):
-        super(ManagerV2, self).__init__(credentials, service)
+    def __init__(self, credentials=None):
+        super(ManagerV2, self).__init__(credentials)
         self._init_clients(self._get_params())
 
     def _init_clients(self, params):
@@ -116,8 +116,8 @@
 
 class ManagerAdmin(clients.Manager):
 
-    def __init__(self, credentials=None, service=None):
-        super(ManagerAdmin, self).__init__(credentials, service)
+    def __init__(self, credentials=None):
+        super(ManagerAdmin, self).__init__(credentials)
         self._init_clients(self._get_params())
 
     def _init_clients(self, params):
@@ -138,8 +138,8 @@
 
 class ManagerV2Unauthed(ManagerV2):
 
-    def __init__(self, credentials=None, service=None):
-        super(ManagerV2Unauthed, self).__init__(credentials, service)
+    def __init__(self, credentials=None):
+        super(ManagerV2Unauthed, self).__init__(credentials)
         self.auth_provider = self._auth_provider_class()(
             credentials=self.auth_provider.credentials,
             auth_url=self.auth_provider.auth_client.auth_url,