nxos_system idempotence fix (#44752)

Signed-off-by: Trishna Guha <trishnaguha17@gmail.com>

lib/ansible/modules/network/nxos/nxos_system.py

@@ -279,10 +279,8 @@ def parse_name_servers(config, vrf_config, vrfs):
     objects = list()
 
     match = re.search('^ip name-server (.+)$', config, re.M)
-    if match:
+    if match and 'use-vrf' not in match.group(1):
         for addr in match.group(1).split(' '):
-            if addr == 'use-vrf' or addr in vrfs:
-                continue
             objects.append({'server': addr, 'vrf': None})
 
     for vrf, cfg in iteritems(vrf_config):