shut validator ipc warning (#2864)

tools/nni_cmd/config_schema.py

 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT license.
 
-import os
 import json
+import logging
+import os
 import netifaces
 from schema import Schema, And, Optional, Regex, Or, SchemaError
 from nni.package_utils import create_validator_instance, get_all_builtin_names, get_builtin_algo_meta
@@ -78,6 +79,7 @@ class AlgoSchema:
         if meta and 'accept_class_args' in meta and meta['accept_class_args'] == False:
             raise SchemaError('classArgs is not allowed.')
 
+        logging.getLogger('nni.protocol').setLevel(logging.ERROR)  # we know IPC is not there, don't complain
         validator = create_validator_instance(algo_type+'s', builtin_name)
         if validator:
             try: