2016-03-24: changed "snmp_scan_function" from ".1.3.6.1.2.1.1.2.0" to ".1.3.6.1.2.1.1.1.0"
2016-07-02: fixed crit/warn to >=
2018-01-09: some fine tuning (changed infotext)
2020-02-13: changed snmp_info from ".1.3.6.1.4.1.9.9.147.1.2.2.2.1.5" to more specific "1.3.6.1.4.1.9.9.147.1.2.2.2.1.5.40"
2020-02-24: added support for Cisco Firepower Threat Defense
2020-04-28: changed item from Cisco ASA connections to Firewall connections --> more clear, with cisco_asa_conn check
2021-03-24: rewrite for CMK 2.0 Check API