fixed code to get token about the empty message

fixed code to get token about the empty message

fixed code to get token about the empty message

Change-Id: Ifbe334f42457c1b2ba801d92cdca540433689938
Signed-off-by: hyuna0213.jo <hyuna0213.jo@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/7387
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Jaewook Jung <jw0213.jung@samsung.com>
Reviewed-by: Ashok Babu Channa <ashok.channa@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/7433
Reviewed-by: Jon A. Cruz <jon@joncruz.org>