Performance improvement using in-operator on dicts

Just a small cleanup for the existing occurrences.

Using the in-operator for hash lookups is faster than using .keys()
http://stackoverflow.com/questions/29314269/why-do-key-in-dict-and-key-in-dict-keys-have-the-same-output

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

@@ -852,7 +852,7 @@ def get_existing(module, prefix, warnings):
             group_route = match_route.groupdict()
 
             for key in key_map:
-                if key not in group_route.keys():
+                if key not in group_route:
                     group_route[key] = ''
             group_route['prefix'] = prefix
             group_route['vrf'] = module.params['vrf']