Touch CLOBBER after bug 957965 landed

CLOBBER

@@ -22,4 +22,4 @@
 # changes to stick? As of bug 928195, this shouldn't be necessary! Please
 # don't change CLOBBER for WebIDL changes any more.
 
-Bug 981166 - Disabling Metro was causing intermittent Windows l10n packaging issues.
+Bug 957865 - Non-clobbered ASAN builds were failing all mochitests after the clang upgrade