message: fix heap corruption bug
diff: @@ -82,7 +82,7 @@ public:
  if (likely(mh) && mh->maxCount() > 1) {
  const auto sizeClass = SizeMap::SizeClass(mh->objectSize());
  Freelist &freelist = _freelist[sizeClass];
  - if (likely(freelist.getAttached() == mh)) {
  + if (likely(freelist.getAttached() == mh && freelist.contains(ptr))) {
  d_assert(mh->refcount() > 0);
  _last = &freelist;
  freelist.free(ptr);
  