add require_once('../lib/base.php'); to webdav.php

apps/files/appinfo/remote.php

@@ -25,6 +25,7 @@
 
 // Do not load FS ...
 $RUNTIME_NOSETUPFS = true;
+require_once('../lib/base.php');
 
 // only need filesystem apps
 $RUNTIME_APPTYPES=array('filesystem','authentication');