bug#51145: Cuirass should tag the Javascript it uses as free

[Mathieu Othacehe]

Hello Maxim,

> They pointed to me that the page wouldn't load in LibreJS, which is true
> (I had forgotten the issue myself, having whitelisted the domain long
> ago).

Fixed with 8726ef9c6572cd07eafd96fce76fd329e9faf469.

Thanks,

Mathieu