You do need to update theme as the latest version has some changes made and the latest Visual Composer plugin included. it is compatible with wordpress 4.5.
But what you’re asking here has nothing to do with theme update and is actually not an issue but part of theme default style.
That is not the url, but the slug of portfolio categories.
If you want to change it to the name instead, then go to file include/view/portfolio/loop-grid.php and find this line:
foreach ($item_categories as $cat)
{
$sort_classes .= $cat->slug.' ';
}
replace with these:
foreach ($item_categories as $cat)
{
$sort_classes .= $cat->name.' ';
}
