Update ProgressUI.php

7-Zip File Manager/ProgressUI.php

@@ -68,7 +68,7 @@ var f_rand = "<?php echo $_GET["rand"] ?>";
 var f_file = "<?php echo $_GET["file"] ?>";
 var f_dir = "<?php echo $_GET["dir"] ?>";
 var f_size = "<?php echo filesize($_GET["file"]); ?>";
-var f_destdir = "<?php echo $_GET["destdir"] ?? ""; ?>";
+var f_destdir = "<?php echo isset($_GET["destdir"]) ? $_GET["destdir"] : ""; ?>";
 var f_time = 1;
 var f_totaltime = 1;
 var f_cancel = false;