csdk: Include config header before any header

It was needed for g++-4.7

Bug: https://jira.iotivity.org/browse/IOT-2244
Change-Id: Iee671616a6e32824be45f1e9424b48e9e073b237
Signed-off-by: Philippe Coval <philippe.coval@osg.samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/19837Tested-by: jenkins-iotivity <jenkins@iotivity.org>
Reviewed-by: Mats Wichmann <mats@linux.com>
Reviewed-by: Uze Choi <uzchoi@samsung.com>

resource/csdk/stack/test/cbortests.cpp

@@ -18,6 +18,7 @@
 //
 //-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
 
+#include "iotivity_config.h"
 
 extern "C"
 {