[libsecret] configure: Use subdir-objects to shut up automake 1.14

[Stefan Walter <stefw src gnome org>]

commit c91de25db1c4063c6e3ac8afcd1d6aaebdf53953
Author: Stef Walter <stefw gnome org>
Date:   Tue Sep 9 15:09:07 2014 +0200

    configure: Use subdir-objects to shut up automake 1.14

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 9119964..86cbb00 100644
--- a/configure.ac
+++ b/configure.ac
@@ -46,7 +46,7 @@ SECRET_AGE=0
 
 AC_CONFIG_MACRO_DIR([build/m4])
 AC_CONFIG_AUX_DIR([build])
-AM_INIT_AUTOMAKE([1.11 tar-ustar foreign -Wno-portability])
+AM_INIT_AUTOMAKE([1.11 tar-ustar foreign -Wno-portability subdir-objects])
 AM_SANITY_CHECK
 AC_CONFIG_HEADERS(config.h)
 AC_CONFIG_SRCDIR([libsecret/secret-value.c])