Fix the rebind exception when calling get_result
Fix the rebind exception when calling get_result

The module used for rebind was set to LtiConsumer instead of the xblock,
which is wrong and causing an silent exception thrown and return 404 to
the client without any indication of the cause.

edx/xblock-lti-consumer,edx/xblock-lti-consumer,edx/xblock-lti-consumer,edx/xblock-lti-consumer