The stats target can be set since commit d06215d0, but wasn't shown by
psql.

Author: Justin Pryzby <justin@telsasoft.com>
Discussion: https://postgr.es/m/20200831050047.GG5450@telsasoft.comReviewed-by: Georgios Kokolatos <gkokolatos@protonmail.com>
Reviewed-by: Tatsuro Yamada <tatsuro.yamada.tf@nttcom.co.jp>