Fix users not being able to change their hide_followers_count setting (#1889)

app/lib/user_settings_decorator.rb

@@ -32,6 +32,7 @@ class UserSettingsDecorator
     user.settings['system_font_ui']      = system_font_ui_preference if change?('setting_system_font_ui')
     user.settings['system_emoji_font']   = system_emoji_font_preference if change?('setting_system_emoji_font')
     user.settings['noindex']             = noindex_preference if change?('setting_noindex')
+    user.settings['hide_followers_count'] = hide_followers_count_preference if change?('setting_hide_followers_count')
     user.settings['flavour']             = flavour_preference if change?('setting_flavour')
     user.settings['skin']                = skin_preference if change?('setting_skin')
     user.settings['aggregate_reblogs']   = aggregate_reblogs_preference if change?('setting_aggregate_reblogs')
@@ -117,6 +118,10 @@ class UserSettingsDecorator
     settings['setting_skin']
   end
 
+  def hide_followers_count_preference
+    boolean_cast_setting 'setting_hide_followers_count'
+  end
+
   def show_application_preference
     boolean_cast_setting 'setting_show_application'
   end