fix: missing add/remove field button on listview settings

closes https://github.com/frappe/frappe/issues/16783

frappe/public/js/frappe/list/list_settings.js

@@ -136,7 +136,7 @@ export default class ListSettings {
 				<div class="control-input-wrapper">
 				${fields}
 				</div>
-				<p class="help-box small text-muted hidden-xs">
+				<p class="help-box small text-muted">
 					<a class="add-new-fields text-muted">
 						+ Add / Remove Fields
 					</a>