Fix /privacy-policy not using the appropriate resource packs (#1853)

Fixes #1852

This was an oversight from last upstream merge, failing to account for
glitch-soc's theming system.

app/controllers/privacy_controller.rb

@@ -3,6 +3,8 @@
 class PrivacyController < ApplicationController
   layout 'public'
 
+  before_action :set_pack
+
   before_action :set_instance_presenter
   before_action :set_expires_in
 
@@ -12,6 +14,10 @@ class PrivacyController < ApplicationController
 
   private
 
+  def set_pack
+    use_pack 'public'
+  end
+
   def set_instance_presenter
     @instance_presenter = InstancePresenter.new
   end