Limit price changes only to channels via channel manager

Remove restriction to change the price of a booking with origin other than direct/web but not synchronized via channel manager.

Currently this warning appears: This booking comes from a travel agency or external sales channel. It is not recommended to change dates, and the system does not allow you to change prices. This ensures that there are no discrepancies between the price shown by the agency and the one registered in the PMS. Which is fine for channels synchronized via channel manager, such as Booking or Expedia.

However, for managing wholesale bookings that are made manually, this limitation is not appropriate.