(js) Improve confirm dialogs for deletions

UI/WebServerResources/js/Contacts/AddressBookController.js

@@ -89,7 +89,8 @@
     
     function confirmDeleteSelectedCards() {
       Dialog.confirm(l('Warning'),
-                     l('Are you sure you want to delete the selected contacts?'))
+                     l('Are you sure you want to delete the selected contacts?'),
+                     { ok: l('Delete') })
         .then(function() {
           // User confirmed the deletion
           var selectedCards = _.filter(vm.selectedFolder.cards, function(card) { return card.selected; });