Updated irssi packages fix security vulnerabilities

It was discovered that Irssi incorrectly handled certain DCC messages. A malicious IRC server could use this issue to cause Irssi to crash, resulting in a denial of service (CVE-2017-9468). Joseph Bisch discovered that Irssi incorrectly handled receiving incorrectly quoted DCC files. A remote attacker could possibly use this issue to cause Irssi to crash, resulting in a denial of service (CVE-2017-9469).