Menu items with external links are not rendered properly

The menus on the home page of GoGreen do not render menu items with external links correctly. The main menu does not render them at all. The two menus in the footer do render them, but the link then does not work.

Steps to reproduce case 1:

1. start GoGreen
2. edit the GoGreen English Website channel
3. click 'Edit menu' for the main menu
4. add a new menu item with an external link
5. close the Edit Menu dialog

Expected: the newly added menu item with an external link is shown in the main menu
Actual: no menu item with an external link is shown

Steps to reproduce case 2:

1. start GoGreen
2. edit the GoGreen English Website channel
3. click 'Edit menu' for one of the menus in the footer of the home page
4. add a new menu item with an external link
5. close the Edit Menu dialog
6. click the added menu item

Expected: the channel manager asks if the external link should be opened or not
Actual: the home page is reloaded