v.25.9Bug Fix (user-visible misbehavior in an official stable release)

ClickHouse Keeper no longer fails

ClickHouse Keeper no longer fails to start on systems where IPv6 is disabled at the kernel level (e.g., RHEL with ipv6.disable=1). It now attempts to fall back to an IPv4 listener if the initial IPv6 listener fails. #85901 (jskong1124).