I placed div outside of ul and moved .ui.resizable-se 20px from right. Is this what you want?
<ul id="unlNotification"style="height: 127.7px;">
<li>qwe</li>
<li>qwe</li>
<li>qwe</li>
...
</ul>
<div class="ui-resizable-handle ui-resizable-se ui-icon ui-icon-gripsmall-diagonal-se" style="z-index: 90;"></div>
css
.ui-resizable-se {
right: 20px;
}