Remove comments related to code from Madrid

CONSUL doesn't implement blank votes via web; the comment was based on
the code used in Madrid, which was actually very complex.

And the concept of "all city" was also specific to Madrid. Poll
questions aren't associated to a geozone, so the geozone will depend on
the poll they're associated to.

spec/system/admin/poll/questions_spec.rb

@@ -151,8 +151,6 @@ describe "Admin poll questions", :admin do
     expect(page).to have_content(question2.title)
   end
 
-  pending "Mark all city by default when creating a poll question from a successful proposal"
-
   context "Poll select box" do
     scenario "translates the poll name in options" do
       poll = create(:poll, name_en: "Name in English", name_es: "Nombre en Español")