fix: use default vae name instead of None on file refresh (lllyasviel#3045)

Author: mashb1t

webui.py

@@ -569,7 +569,7 @@ def refresh_files_clicked():
                     modules.config.update_files()
                     results = [gr.update(choices=modules.config.model_filenames)]
                     results += [gr.update(choices=['None'] + modules.config.model_filenames)]
-                    results += [gr.update(choices=['None'] + modules.config.vae_filenames)]
+                    results += [gr.update(choices=[flags.default_vae] + modules.config.vae_filenames)]
                     if not args_manager.args.disable_preset_selection:
                         results += [gr.update(choices=modules.config.available_presets)]
                     for i in range(modules.config.default_max_lora_number):