Subscribers import: Step1 also uses the email regexp to validate emails [MAILPOET-1288]

assets/js/src/subscribers/importExport/import.js

@@ -164,8 +164,9 @@ define(
                 // is the email in 'mailto:email' format?
                 email = test[1].trim();
               }
-              // test for valid characters using WP's rule (https://core.trac.wordpress.org/browser/tags/4.7.3/src/wp-includes/formatting.php#L2902)
+
-              if (!/^[a-zA-Z0-9!#$%&'*+/=?^_`{|}~.-@]+$/.test(email)) {
+              // validate email
+              if (!window.mailpoet_email_regex.test(email)) {
                 return false;
               }
               return email;