New csf v7.72

Changes:

• Added new option PT_SSHDHUNG. Terminate hung SSHD sessions. When under an SSHD login attack, SSHD processes are often left hung after their connecting IP addresses have  been blocked. This option will terminate such processes. See csf.conf for more info
• Added new binaries to csf.pignore on existing cPanel installations to cater for v11.50 and CentOS v7
• LF_CONSOLE_EMAIL_ALERT and LF_WEBMIN_EMAIL_ALERT now default to 1 for new installations
• Updated Server Check ipv6 detection
• Updated sanity checks