fail2ban changes:
- nftables support (iptables dependency removed)
- python3 support (old package patches removed)
- Upstream patches backports:
- filter.d/dropbear.conf: failregex extended to match different format of "Exit before auth" message
- cherry-pick from debian: debian default banactions are nftables, systemd backend for sshd
- Removed unresponsive/unreachable maintainer.
Fixes: https://github.com/openwrt/packages/issues/23015 ("fail2ban: very old version")
Signed-off-by: Andrey Zotikov <andrey.zotikov@gmail.com>
