add missed dependency on jquery ui core module

Author: omiroshnichenko

app/code/Magento/Ui/view/base/web/js/modal/modal.js

@@ -15,6 +15,7 @@ define([
     'text!ui/template/modal/modal-custom.html',
     'Magento_Ui/js/lib/key-codes',
     'jquery-ui-modules/widget',
+    'jquery-ui-modules/core',
     'mage/translate'
 ], function ($, _, template, popupTpl, slideTpl, customTpl, keyCodes) {
     'use strict';