Let CLI print exception traceback from 'debuginfo'

Response 'debuginfo' is used to carry server traceback in case of
error. If 'debuginfo' is not empty, append it to exception message,
so traceback will be printed together with message.

Change-Id: Id7900b64ec7fc9f906253ef0e2d754c2baa76067
Closes-Bug: #1255590
Merge "Let CLI print exception traceback from 'debuginfo'"