[gnome-builder] build: disable xdg-app if PKG_CHECK_MODULES() fails

[Christian Hergert <chergert src gnome org>]

commit 921248f34c3d7b67e3a6f0a59a309c16c659e93e
Author: Christian Hergert <chergert redhat com>
Date:   Mon Feb 15 21:15:07 2016 -0800

    build: disable xdg-app if PKG_CHECK_MODULES() fails

 plugins/xdg-app/configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/plugins/xdg-app/configure.ac b/plugins/xdg-app/configure.ac
index 53875d6..6fecd09 100644
--- a/plugins/xdg-app/configure.ac
+++ b/plugins/xdg-app/configure.ac
@@ -17,7 +17,7 @@ AS_IF([test "$enable_xdg_app_plugin" != no],[
               AC_MSG_ERROR([--enable-xdg-app-plugin requires xdg-app >= xdg_app_required_version])
        ])
 
-       enable_xdg_app_plugin=yes
+       enable_xdg_app_plugin=$have_xdg_app
 ])
 
 AM_CONDITIONAL(ENABLE_XDG_APP_PLUGIN, test x$enable_xdg_app_plugin = xyes)