Squelch border on dropdown hidden elements

The auth drop down in the top right of the sidebar was showing a border
on the "top" entry because the first one was hidden.

h/css/common.scss

@@ -306,7 +306,7 @@ blockquote {
   position: absolute;
   z-index: 2;
 
-  li {
+  li:not(.ng-hide) {
     cursor: pointer;
     line-height: 1;
     text-align: left;