ticker addon doesn't work with firefox 57

[mmouse-]

Firefox release 57.0 disables the old extension type, and doesn't let me re-enable it.

So bitcoin-price-ticker won't work any more.

[sebaslogen]

Unfortunately, the new Firefox doesn't support this kind of extension anymore (with text or numbers in the navigation bar) so there is no way I can make it work in the new Firefox.