Remove autoload trigger

I'm not sure why the code didn't work without this line, but it doesn't
seem to be necessary anymore (maybe after upgrading Ruby or Rails?).

I'm removing it now because... why not now? :) The Ruby interpreter is
raising a warning due to this line, and in Ruby 2.5 constant lookup has
changed slightly (although I don't think this line is affected by that
change).

Note about the change in the Setting model: Ruby actually ignores return
values in setter methods, so the line isn't necessary.

.rubocop.yml

@@ -186,6 +186,9 @@ Lint/ShadowingOuterLocalVariable:
 Lint/UselessAssignment:
   Enabled: true
 
+Lint/Void:
+  Enabled: true
+
 Performance/CompareWithBlock:
   Enabled: true
 

app/controllers/polls_controller.rb

@@ -9,8 +9,6 @@ class PollsController < ApplicationController
   has_filters %w[current expired]
   has_orders %w[most_voted newest oldest], only: :show
 
-  ::Poll::Answer # trigger autoload
-
   def index
     @polls = Kaminari.paginate_array(
       @polls.created_by_admin.not_budget.send(@current_filter).includes(:geozones).sort_for_list

app/models/setting.rb

@@ -38,7 +38,6 @@ class Setting < ApplicationRecord
       setting = find_by(key: key) || new(key: key)
       setting.value = value.presence
       setting.save!
-      value
     end
 
     def rename_key(from:, to:)