Update ce_ntp to fix bugs

lib/ansible/modules/network/cloudengine/ce_ntp.py

@@ -574,7 +574,8 @@ class Ntp(object):
                         cli_str = "%s %s" % (
                             "undo ntp unicast-peer ipv6", self.address)
                 if (self.vpn_name) and (self.vpn_name != '_public_'):
-                    cli_str = "%s %s" % (cli_str, self.vpn_name)
+                    cli_str = "%s %s %s" % (
+                        cli_str, "vpn-instance", self.vpn_name)
 
         self.updates_cmd.append(cli_str)