Fix contrast between background and form elements on some pages (#31266)

app/controllers/mail_subscriptions_controller.rb

@@ -5,7 +5,6 @@ class MailSubscriptionsController < ApplicationController
 
   skip_before_action :require_functional!
 
-  before_action :set_body_classes
   before_action :set_user
   before_action :set_type
 
@@ -25,10 +24,6 @@ class MailSubscriptionsController < ApplicationController
     not_found unless @user
   end
 
-  def set_body_classes
-    @body_classes = 'lighter'
-  end
-
   def set_type
     @type = email_type_from_param
   end