Update _validators.py

src/azure-cli/azure/cli/command_modules/storage/_validators.py

@@ -617,6 +617,7 @@ def validator(cmd, namespace):
         clear_content_settings = ns.pop('clear_content_settings', False)
 
         # retrieve the existing object properties for an update
+        props = None
         if update and not clear_content_settings:
             account = ns.get('account_name')
             key = ns.get('account_key')
@@ -672,12 +673,12 @@ def validator(cmd, namespace):
         )
 
         # if update, fill in any None values with existing
-        if update:
+        if update and props:
             if not clear_content_settings:
                 for attr in ['content_type', 'content_disposition', 'content_encoding', 'content_language',
                              'content_md5', 'cache_control']:
                     if getattr(new_props, attr) is None:
-                        setattr(new_props, attr, getattr(props, attr))  # pylint: disable=used-before-assignment
+                        setattr(new_props, attr, getattr(props, attr))
         else:
             if guess_from_file:
                 new_props = guess_content_type(ns[guess_from_file], new_props, settings_class)