zabbix_agentd: Update to 6.0.30 (LTS)

zabbix_agentd: Update to 6.0.30 (LTS)

- Update from version 6.0.27 to 6.0.30
- Update of rootfile not required

Bugs fixed:
- ZBX-23853: Fixed duplicate agent check timestamps when time shifts back due to system clock synchronization

Full changelogs since 6.0.27:
- https://www.zabbix.com/rn/rn6.0.28
- https://www.zabbix.com/rn/rn6.0.29
- https://www.zabbix.com/rn/rn6.0.30
Reviewed-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>