[gtkmm-documentation] Create only .tar.xz tarballs

[Kjell Ahlstedt <kjellahl src gnome org>]

commit b1afa84718ecede880a405522254ae76225a3b99
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Thu Nov 8 18:35:38 2018 +0100

    Create only .tar.xz tarballs
    
    * configure.ac: This is what ftp.gnome.org wants, so this avoids
    it doing any repackaging. This is what gtkmm does.

 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/configure.ac b/configure.ac
index b29f1dd..9972add 100644
--- a/configure.ac
+++ b/configure.ac
@@ -10,7 +10,7 @@ AC_CONFIG_AUX_DIR([build])
 AC_CONFIG_MACRO_DIR([build])
 AC_CONFIG_HEADERS([build/config.h])
 
-AM_INIT_AUTOMAKE([1.9 -Wno-portability check-news dist-bzip2 no-define nostdinc tar-ustar])
+AM_INIT_AUTOMAKE([1.9 -Wno-portability check-news no-dist-gzip dist-xz tar-ustar no-define nostdinc])
 # Support silent build rules.
 # Disable by either passing --disable-silent-rules to configure or passing V=1 to make.
 m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])