run egw destructor explizit for merge-downloads to allow eg. notifications emails in shutdown handler

api/src/Storage/Merge.php

@@ -2040,6 +2040,10 @@ abstract class Merge
 			}
 			Api\Header\Content::type($header['name'], $header['mime'], $header['filesize']);
 			readfile($result);
+
+			// run egw destructor now explicit, in case a (notification) email is send via Egw::on_shutdown(),
+			// as stream-wrappers used by Horde Smtp fail when PHP is already in destruction
+			$GLOBALS['egw']->__destruct();
 			exit;
 		}