test relies on removed CONFIG entry

[Habbie]

list-max-ziplist-entries was removed (in 3.2-rc1 as far as I can tell). I cannot immediately figure out a different key that has been stable over a long time to replace it with. Alternatively we could make the test conditional on < versus > 3.2 and replace it with hash-max-ziplist-entries which exists at least in 3.2.5 and current unstable.