Remove not used server creation from test_server_rescue

test_server_rescue created a server in the setUpClass
 which is not in use in the current code base.

Change-Id: I9487ddf6db8fda5b5fe6aa3f8787b56b8c865cf5
diff --git a/tempest/api/compute/servers/test_server_rescue.py b/tempest/api/compute/servers/test_server_rescue.py
index ab98d88..b737888 100644
--- a/tempest/api/compute/servers/test_server_rescue.py
+++ b/tempest/api/compute/servers/test_server_rescue.py
@@ -54,7 +54,6 @@
 
         # Server for positive tests
         resp, server = cls.create_test_server(wait_until='BUILD')
-        resp, resc_server = cls.create_test_server(wait_until='ACTIVE')
         cls.server_id = server['id']
         cls.password = server['adminPass']
         cls.servers_client.wait_for_server_status(cls.server_id, 'ACTIVE')