unbreak automatic focusing of invalid field in phone home setup

In addition to fixing it we're trying not to focus first invalid
element if another invalid element is already focused. This sadly,
doesn't work on IE8, seemingly because at form submit time focus is
already on next button.

Change-Id: I38d11934817a6a41fdc361e5822f03158959ed8e
Reviewed-on: http://review.couchbase.org/11793
Reviewed-by: Steve Yen <steve.yen@gmail.com>
Tested-by: Aliaksey Kandratsenka <alkondratenko@gmail.com>

priv/public/js/app.js

@@ -756,9 +756,12 @@ var NodeDialog = {
       }
 
       if (errors.length) {
+        var invalidFields = dialog.find('.invalid');
         renderTemplate('update_notifications_errors', errors);
         $('#update_notifications_errors_container').show();
-        try {invalidFields[0].focus();} catch (e) {}
+        if (invalidFields.length && !_.include(invalidFields, document.activeElement)) {
+          setTimeout(function () {try {invalidFields[0].focus();} catch (e) {}}, 10);
+        }
         return;
       }