fix model override logic

    stored_opts = {k: opts.data[k] for k in p.override_settings.keys()}

    try:

        # after running refiner, the refiner model is not unloaded - webui swaps back to main model here

        if shared.sd_model.sd_checkpoint_info.title != opts.sd_model_checkpoint:

            sd_models.reload_model_weights()

        # if no checkpoint override or the override checkpoint can't be found, remove override entry and load opts checkpoint

        # and if after running refiner, the refiner model is not unloaded - webui swaps back to main model here, if model over is present it will be reloaded afterwards

        if sd_models.checkpoint_aliases.get(p.override_settings.get('sd_model_checkpoint')) is None:

            p.override_settings.pop('sd_model_checkpoint', None)

            sd_models.reload_model_weights()