Here's how you can change your hrefs for any node/add link to https using jQuery:
<?php
$(document).ready(function(){
$('a').each(function(){
href = $(this).attr('href');
splitA = href.split('/');
if (splitA[1]=='node' && splitA[2]=='add') {
$(this).attr('href', 'https://'+location.host+href);
}
});
});
?>