[1.6.x] Fixed overflow for the "Recent Actions" widget on the admin index.

Previously the CSS targeted "li.changelink" and therefore didn't
work for the "add" and "delete" actions.

Refs #14868.

Backport of 33fc083b0d from master

django/contrib/admin/static/admin/css/dashboard.css

@@ -23,8 +23,8 @@ ul.actionlist li {
     list-style-type: none;
 }
 
-ul.actionlist li.changelink {
+ul.actionlist li {
     overflow: hidden;
     text-overflow: ellipsis;
     -o-text-overflow: ellipsis;
-}
+}