Sizzle: fix failing test in IE: malformed HTML

diff --git a/src/sizzle b/src/sizzle
index 6ed5a849f8437d2903d66927151bed6f3e5f3915..21ca31806d5f71df9f20aea9220bcddfb7a0a050 160000 (submodule)
--- a/src/sizzle
+++ b/src/sizzle
@@ -1 +1 @@
-Subproject commit 6ed5a849f8437d2903d66927151bed6f3e5f3915
+Subproject commit 21ca31806d5f71df9f20aea9220bcddfb7a0a050