package/libs/libtool: Switch to xz tarball

Switch to xz tarball, there's no point pulling two different tarballs of the same source code (tools/libtool uses xz).

Signed-off-by: Daniel Engberg <daniel.engberg.lists@pyret.net>

package/libs/libtool/Makefile

@@ -11,9 +11,9 @@ PKG_NAME:=libtool
 PKG_VERSION:=2.4
 PKG_RELEASE:=1
 
-PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.gz
+PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.xz
 PKG_SOURCE_URL:=@GNU/libtool
-PKG_MD5SUM:=b32b04148ecdd7344abc6fe8bd1bb021
+PKG_MD5SUM:=afcce660d3dc54c63a0a5ba3cf05272239dc3c54bbeba20f6bad250f9dc007ae
 
 PKG_LICENSE:=GPL-2.0+
 PKG_LICENSE_FILES:=COPYING