[Bug-gnuzilla] free add-on ublock origin not listed on addons page for icecat

[Ganesh Ajjanagadde]

https://github.com/gorhill/uBlock is a very efficient and powerful ad
blocker for internet browsers, and in particular firefox and its
derivatives. Furthermore, it is released under GPLv3, as can be
verified from the LICENSE.txt in the repository.
Please add this to the lists of addons for icecat.

As a side note, unlike Adblock Plus, it does not have any notion of
"ok advertising".
Because of this and lower browser footprint (as detailed at the
author's github repo),
it has become a far better ad blocking solution than adblock plus,
and hence I also recommend you consider using this for the icecat browser
instead of adblock based solutions (spyblock).

Thanks,
Ganesh Ajjanagadde