You would need to add this to 'public/assets/javascript/og/ContactManager.js'. You'll find at line 287 this:
}]);
cm.defaultSortable = false;
Change it to this:
},{
id: 'createdBy',
header: lang("created by"),
dataIndex: 'createdBy',
width: 120
}]);
cm.defaultSortable = false;
Cheers
