Update to use Ruffles version once it's fixed

[lhl]

See:
ruffle-rs/ruffle#1629
ruffle-rs/ruffle#335
ruffle-rs/ruffle#340

[ousia]

The two last issues are solved, so I think nothing stands in the way to implement a newer version at https://randomfoo.net/oscon/2002/lessig/free.html.

Many thanks for your excellent work.

[ousia]

@lhl, all three issues have been fixed.

I sent a PR that also fixes the need of the plugin to browse the SWF file in the page.

Many thanks for your work with this presentation.