Expose a bug when authorize request token
Expose a bug when authorize request token

Keystone raise 500 error when authorize request token
with invalid body.

This patch expose the bug that keystone raise 500
error instead of 400 in this case.

Change-Id: I3ddeebf8a46467ed090d8831fd8cf35edee7ce04
Partial-Bug: #1736875

openstack/keystone,mahak/keystone,mahak/keystone,openstack/keystone,openstack/keystone,mahak/keystone