Prestashop: Remove Default Shipping Fee Being Added To Total Price at Shopping Cart

If you've been developing e-commerce websites with Prestashop, one main problem that has not been solved in the latest release (Prestashop 1.1) is that the default shipping is immediately added when checking out at the shopping cart. This poses a problem when there are more than one option for shipping methods, and their prices differ from one another. Here is a very simple hack to prevent the default shipping fee from being added to the total price at the Shopping Cart summary page without the need to modify any code: