modified detection

• 501461tenable_ot_moxa_CVE-2016-0876.nasl • 1.3
• 501520tenable_ot_moxa_CVE-2016-5804.nasl • 1.3
• 501426tenable_ot_moxa_CVE-2016-0879.nasl • 1.3
• 501911tenable_ot_dell_CVE-2016-5685.nasl • 1.2
• 500605tenable_ot_siemens_CVE-2016-8562.nasl • 1.11
• 501490tenable_ot_moxa_CVE-2016-8346.nasl • 1.3