Remove CONF reference from servers client

To move server client to tempest-lib, this patch moves
CONF.compute_feature_enabled to the client setting.

Change-Id: I835dbfdb5b58603a863bf26ad8e72d7748e0fc88
diff --git a/tempest/clients.py b/tempest/clients.py
index 7a41f32..fbf240c 100644
--- a/tempest/clients.py
+++ b/tempest/clients.py
@@ -239,7 +239,11 @@
             SecurityGroupDefaultRulesClientJSON(self.auth_provider, **params))
         self.certificates_client = CertificatesClientJSON(self.auth_provider,
                                                           **params)
-        self.servers_client = ServersClientJSON(self.auth_provider, **params)
+        self.servers_client = ServersClientJSON(
+            self.auth_provider,
+            enable_instance_password=CONF.compute_feature_enabled
+                .enable_instance_password,
+            **params)
         self.limits_client = LimitsClientJSON(self.auth_provider, **params)
         self.images_client = ImagesClientJSON(self.auth_provider, **params)
         self.keypairs_client = KeyPairsClientJSON(self.auth_provider, **params)
diff --git a/tempest/services/compute/json/servers_client.py b/tempest/services/compute/json/servers_client.py
index b01fbf1..bd4fd0e 100644
--- a/tempest/services/compute/json/servers_client.py
+++ b/tempest/services/compute/json/servers_client.py
@@ -24,14 +24,17 @@
 from tempest.api_schema.response.compute.v2 import servers as schema
 from tempest.common import service_client
 from tempest.common import waiters
-from tempest import config
 from tempest import exceptions
 
-CONF = config.CONF
-
 
 class ServersClientJSON(service_client.ServiceClient):
 
+    def __init__(self, auth_provider, service, region,
+                 enable_instance_password=True, **kwargs):
+        super(ServersClientJSON, self).__init__(
+            auth_provider, service, region, **kwargs)
+        self.enable_instance_password = enable_instance_password
+
     def create_server(self, name, image_ref, flavor_ref, **kwargs):
         """
         Creates an instance of a server.
@@ -93,7 +96,7 @@
         # with return reservation id set True
         if 'reservation_id' in body:
             return service_client.ResponseBody(resp, body)
-        if CONF.compute_feature_enabled.enable_instance_password:
+        if self.enable_instance_password:
             create_schema = schema.create_server_with_admin_pass
         else:
             create_schema = schema.create_server
@@ -275,7 +278,7 @@
         if 'disk_config' in kwargs:
             kwargs['OS-DCF:diskConfig'] = kwargs['disk_config']
             del kwargs['disk_config']
-        if CONF.compute_feature_enabled.enable_instance_password:
+        if self.enable_instance_password:
             rebuild_schema = schema.rebuild_server_with_admin_pass
         else:
             rebuild_schema = schema.rebuild_server