[FIX] website_sale: Pay Now button is clickable even without clicking policies and conditions

Steps to reproduce the bug:

-Go to the shop
-Add an item to card
-Checkout
-Insert address info
-Click proceed
-Enable "Accept Terms & Conditions"
-With the HTML Editor, remove the attribute checked="checked" in template Accept Terms & Conditions

Bug:

-Pay Now button is clickable but the Policy and Procedures box was not checked.

opw:771418

addons/website_sale/static/src/js/website_sale_payment.js

@@ -6,9 +6,10 @@ var ajax = require('web.ajax');
 $(document).ready(function () {
     // If option is enable
     if ($("#checkbox_cgv").length) {
-      $("#checkbox_cgv").click(function() {
+      var enabling_button = function() {
         $("div.oe_sale_acquirer_button").find('input, button').prop("disabled", !this.checked);
-      });
+      };
+      $("#checkbox_cgv").click(enabling_button).each(enabling_button);
     }
 
     // When choosing an acquirer, display its Pay Now button