package/exim: change tarball compression to xz

Signed-off-by: Jerzy Grzegorek <jerzy.m.grzegorek@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/exim/exim.hash

@@ -1,2 +1,2 @@
-# Locally calculated
-sha256 1c853bc960dff0a0e51e3e28bc4a4a8165b58b41bb64ea3abb90f254d9947a8c  exim-4.89.1.tar.bz2
+# Locally calculated after checking pgp signature
+sha256 1a21322a10e2da9c0bd6a2a483b6e7ef8fa7f16efcab4c450fd73e7188f5fa94  exim-4.89.1.tar.xz

package/exim/exim.mk

@@ -5,7 +5,7 @@
 ################################################################################
 
 EXIM_VERSION = 4.89.1
-EXIM_SOURCE = exim-$(EXIM_VERSION).tar.bz2
+EXIM_SOURCE = exim-$(EXIM_VERSION).tar.xz
 EXIM_SITE = ftp://ftp.exim.org/pub/exim/exim4
 EXIM_LICENSE = GPL-2.0+
 EXIM_LICENSE_FILES = LICENCE