Unbreak commit 142387501dcc7b7ecfd34bcaff9b185bd7414874
Unbreak commit 142387501dcc7b7ecfd34bcaff9b185bd7414874

While working on the mentioned commit I forgot to test old versions.
PG_XXX_[MIN|MAX] was added in 9.5.

Reported by @grandegoiania (issue #37).

eulerto/pgquarrel,eulerto/pgquarrel