[gthumb] automake: added the subdir-objects option as requested by a warning

[Paolo Bacchilega <paobac src gnome org>]

commit 966b4b651a9d06bf0e3148b762fbce8b73fe4833
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Sat Oct 19 08:29:50 2013 +0200

    automake: added the subdir-objects option as requested by a warning

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 890f44a..d2121f4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -10,7 +10,7 @@ AC_PREREQ(2.63)
 AC_INIT([gthumb], [gthumb_version],
         [http://bugzilla.gnome.org/enter_bug.cgi?product=gthumb],
         [gthumb])
-AM_INIT_AUTOMAKE([1.11 foreign no-dist-gzip dist-xz tar-ustar])
+AM_INIT_AUTOMAKE([1.11 foreign no-dist-gzip dist-xz tar-ustar subdir-objects])
 
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_MACRO_DIR([m4])