Read ssh/telnet port from /etc: function and regex update

[Martin-Zeithaml]

Update of untested #326:

• fs.fileExists should be without fs
• Regex is missing start (^), it was returning port of otelnet on our system

With the debug mode

2024-11-07 11:12:07.193 <ZWED:33949259> ZWESVUSR DEBUG (plugins-init) readPortFromUnixConfig: /etc/ssh/sshd_config -> "Port 123" -> 123
2024-11-07 11:12:07.198 <ZWED:33949259> ZWESVUSR DEBUG (plugins-init) readPortFromUnixConfig: /etc/services -> "telnet          345" -> 345

[Martin-Zeithaml]

@1000TurquoisePogs The previous PR was not tested and unfortunately there were bugs.