Conflicts:
app/controllers/accounts_controller.rb
app/javascript/mastodon/locales/pl.json
app/views/about/more.html.haml
Conflicts in `accounts_controller.rb` resolved by taking upstream's
version + our `use_pack`.
Conflicts in `pl.json` resolved by taking upstream's changes.
Conflicts in `aboute/more.html.haml` resolved by taking upstream's changes.