update muffinstracker

diff --git a/public/muffinstracker b/public/muffinstracker
index ce517337f3ee552cbdba7a72a2fa28b0ffa5e551..640f31aed8e281731896f3778be8dd42f407ff42 160000 (submodule)
--- a/public/muffinstracker
+++ b/public/muffinstracker
@@ -1 +1 @@
-Subproject commit ce517337f3ee552cbdba7a72a2fa28b0ffa5e551
+Subproject commit 640f31aed8e281731896f3778be8dd42f407ff42