[gnome-boxes] Use subdir-objects in Automake init

[Zeeshan Ali Khattak <zeeshanak src gnome org>]

commit 0a1c319a0777c34e98488412b49f74882b0f3960
Author: Kerrick Staley <kerrick kerrickstaley com>
Date:   Sat Aug 31 14:57:10 2013 -0700

    Use subdir-objects in Automake init
    
    Automake 1.14 prints a warning and build fails if this is not explictly
    specified.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=707199

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 0500108..2668156 100644
--- a/configure.ac
+++ b/configure.ac
@@ -10,7 +10,7 @@ AC_CONFIG_MACRO_DIR([m4])
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_AUX_DIR([build-aux])
 
-AM_INIT_AUTOMAKE([1.11 dist-xz no-dist-gzip tar-ustar foreign -Wall -Werror])
+AM_INIT_AUTOMAKE([1.11 dist-xz no-dist-gzip tar-ustar foreign -Wall -Werror subdir-objects])
 AM_MAINTAINER_MODE([enable])
 
 AM_SILENT_RULES([yes])