Update QUnit.

diff --git a/test/qunit b/test/qunit
index d97b37ec322136406790e75d03333559f38bbecb..d4f23f8a882d13b71768503e2db9fa33ef169ba0 160000 (submodule)
--- a/test/qunit
+++ b/test/qunit
@@ -1 +1 @@
-Subproject commit d97b37ec322136406790e75d03333559f38bbecb
+Subproject commit d4f23f8a882d13b71768503e2db9fa33ef169ba0