pg_basebackup: Fix check for MINIMUM_VERSION_FOR_WAL_SUMMARIES

pg_basebackup: Fix check for MINIMUM_VERSION_FOR_WAL_SUMMARIES

MINIMUM_VERSION_FOR_WAL_SUMMARIES is used to check if the directory
pg_wal/summaries/ should be created in a base backup, but its condition
was reversed: pg_wal/summaries/ would be created when taking base
backups from backends of v16 and older versions, but it should be
created in base backups taken from backends of v17 and newer versions.

Author: Artur Zakirov
Reviewed-by: Yugo Nagata, Nazir Bilal Yavuz
Discussion: https://postgr.es/m/CAKNkYnzkkQ0gb_ZmLTY0r2-qV1q6imXgcCWxdA6UoA6yJkujGg@mail.gmail.com