Remove unused import

Author: troydai

src/command_modules/azure-cli-keyvault/azure/cli/command_modules/keyvault/commands.py

@@ -7,7 +7,6 @@
     keyvault_client_vaults_factory, keyvault_data_plane_factory)
 
 from azure.cli.core.commands import CliCommandType
-from azure.cli.core.util import empty_on_404
 
 from azure.cli.command_modules.keyvault._validators import (
     process_secret_set_namespace, process_certificate_cancel_namespace)