Updated mgetty packages fix security vulnerabilities

Updated mgetty packages fix security vulnerabilities: The function do_activate() did not properly sanitize shell metacharacters to prevent command injection (CVE-2018-16741). Stack-based buffer overflow that could have been triggered via a command-line parameter (CVE-2018-16742). The command-line parameter username wsa passed unsanitized to strcpy(), which could have caused a stack-based buffer overflow (CVE-2018-16743). The mail_to parameter was not sanitized, leading to command injection if untrusted input reached reach it (CVE-2018-16744). The mail_to parameter was not sanitized, leading to a buffer overflow if long untrusted input reached it (CVE-2018-16745).