modified detection

• 501427tenable_ot_moxa_CVE-2017-16727.nasl • 1.10
• 500862tenable_ot_schneider_CVE-2017-6026.nasl • 1.13
• 500871tenable_ot_schneider_CVE-2017-6028.nasl • 1.14
• 500867tenable_ot_schneider_CVE-2017-6030.nasl • 1.13
• 501682tenable_ot_siemens_CVE-2017-12734.nasl • 1.10
• 501675tenable_ot_siemens_CVE-2017-12735.nasl • 1.10
• 500107tenable_ot_siemens_CVE-2017-9946.nasl • 1.15
• 500105tenable_ot_siemens_CVE-2017-9947.nasl • 1.15