Removed NTP_SERVER1 usage.

tests/test_ntp.py

@@ -24,7 +24,7 @@ print('Checking NTP server conforms to conf')
 if os.path.isfile('../utils.py'):
     es_utils = imp.load_source('es_utils', '../utils.py')
     conf = es_utils.load_conf()
-    NTP_SERVER = conf.get('NTP_SERVER') or conf.get('NTP_SERVER1') or 'ntp.ubuntu.com'
+    NTP_SERVER = conf.get('NTP_SERVER') or 'ntp.ubuntu.com'
 
     with open('/etc/ntp.conf', 'r') as f:
         d = f.read()