generate list failed with `to_json': source sequence is illegal/malformed utf-8

[wenerme]

/build/lib/wayback_machine_downloader.rb:182:in `to_json': source sequence is illegal/malformed utf-8 (JSON::GeneratorError)
        from /build/lib/wayback_machine_downloader.rb:182:in `block in list_files'
        from /build/lib/wayback_machine_downloader.rb:181:in `each'
        from /build/lib/wayback_machine_downloader.rb:181:in `list_files'
        from /build/bin/wayback_machine_downloader:70:in `<top (required)>'
        from /usr/local/bundle/bin/wayback_machine_downloader:17:in `load'
        from /usr/local/bundle/bin/wayback_machine_downloader:17:in `<main>'

seems some url contain some invalid % escape sequence