update stax.dtd file path

andrug

21.27.2007 19966f8ae75af28ce639c1516119c641f905d828

 opends/tests/functional-tests/testcases/backends/backup-tasks.xml

@@ -1,5 +1,5 @@
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE stax SYSTEM "../../shared/stax.dtd">
<!DOCTYPE stax SYSTEM "../../../shared/stax.dtd">
<!--
 ! CDDL HEADER START
 !