printer xml BUGFIX printing anydata tree without namespace

Refs #1958
diff --git a/src/printer_xml.c b/src/printer_xml.c
index e45eb2b..e22924c 100644
--- a/src/printer_xml.c
+++ b/src/printer_xml.c
@@ -287,8 +287,10 @@
     /* print node name */
     ly_print_(pctx->out, "%*s<%s", INDENT, node->name.name);
 
-    /* print default namespace */
-    xml_print_ns_opaq(pctx, node->format, &node->name, LYXML_PREFIX_DEFAULT);
+    if (node->name.prefix || node->name.module_ns) {
+        /* print default namespace */
+        xml_print_ns_opaq(pctx, node->format, &node->name, LYXML_PREFIX_DEFAULT);
+    }
 
     /* print attributes */
     LY_CHECK_RET(xml_print_attr(pctx, node));