The previous entrypoint treated clickhouse-backup as required: a download failure
(rate-limit or transient network) caused install_clickhouse_backup to return 1 which
with set -e exited the entrypoint before /entrypoint.sh ran. ClickHouse never started,
the swarm restarted it, the download was retried, amplifying the throttle -> crash-loop
-> deploy timeout (cc-ci Q4.7b).
Fix: install_clickhouse_backup || true — the server starts even if the backup tool
cannot be fetched. Backup/restore degrades until a later restart fetches it.
Also: fix stray trailing quote in backupbot.restore.post-hook; bump
CLICKHOUSE_ENTRYPOINT_VERSION v3->v4 (config content changed).
