Description of problem:
Looks related to the jquery which was removed (obsolete):
http://gitweb.mageia.org/web/www/commit/?id=20bf446342726c2b7b0dd0ff0fbcb453fe3bf734

<script src="//static.mageia.org/g/js/jquery-1.10.1.min.js"></script>

The new url is https://static.mageia.org/g/js/jquery.min.js

But I suggest to remove:

<script src="//static.mageia.org/g/js/jquery-1.10.1.min.js"></script>
<script>
        $("#hmgn").load("//nav.mageia.org/html/").delay(10).slideDown();
</script>

and use direclty:

<script src="//nav.mageia.org/js/"></script>