configure.ac: force autotool to use star

To circumvent the 99 character filename limit.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>
diff --git a/configure.ac b/configure.ac
index 472ee8f..52da827 100644
--- a/configure.ac
+++ b/configure.ac
@@ -26,7 +26,7 @@
         fi
 fi
 
-AM_INIT_AUTOMAKE([1.11 foreign no-dist-gzip dist-xz])
+AM_INIT_AUTOMAKE([1.11 foreign no-dist-gzip dist-xz tar-ustar])
 
 AM_SILENT_RULES([yes])