Remove update_totals/persist_totals delegation

These are private methods on OrderUpdater, so there's no need for doing
this. It's been like like this since 2.2ish when these were made
private, but no one removed this.

core/app/models/spree/order.rb

@@ -138,7 +138,6 @@ def self.find_by_param!(value)
       find_by! number: value
     end
 
-    delegate :update_totals, :persist_totals, to: :updater
     delegate :firstname, :lastname, to: :bill_address, prefix: true, allow_nil: true
     alias_method :billing_firstname, :bill_address_firstname
     alias_method :billing_lastname, :bill_address_lastname