irssi: security bump to version 0.8.20

Fixes two remote crash issues since version 0.8.17

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/irssi/irssi.hash

@@ -1,2 +1,2 @@
 # Locally calculated after checking pgp signature
-sha256	4ca0040548e814ea93eb7d602ab7d6d379afcbbdf10e84160523ce69c73ee5d3	irssi-0.8.19.tar.xz
+sha256	7882c4e821f5aac469c5e69e69d7e235f4986101285c675e81a9a95bfb20505a	irssi-0.8.20.tar.xz

package/irssi/irssi.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-IRSSI_VERSION = 0.8.19
+IRSSI_VERSION = 0.8.20
 IRSSI_SOURCE = irssi-$(IRSSI_VERSION).tar.xz
 # Do not use the github helper here. The generated tarball is *NOT* the
 # same as the one uploaded by upstream for the release.