Fix extra networks save preview image geninfo

        assert is_allowed, f'writing to {filename} is not allowed'

        if geninfo:

            ext = os.path.splitext(filename)[1].lower()

            if ext == '.png':

                pnginfo_data = PngImagePlugin.PngInfo()

                pnginfo_data.add_text('parameters', geninfo)

                image.save(filename, pnginfo=pnginfo_data)

            elif ext in ('.jpg', '.jpeg', '.webp'):

                exif_bytes = piexif.dump({

                    'Exif': {piexif.ExifIFD.UserComment: piexif.helper.UserComment.dump(geninfo or '',

                                                                                        encoding='unicode')}

                })

                image.save(filename, exif=exif_bytes, quality=shared.opts.jpeg_quality)

            else:

                image.save(filename)

        else:

            image.save(filename)