The 'nova get-password' command shows a passowrd as bytes
instead of string in Python 3 currently.
It should be shown as string.
So fix it.
Co-Authored-By: Takashi Natsume <natsume.takashi@lab.ntt.co.jp>
Change-Id: Ibcfb071fcc3c74535b800295ec95ca5ec8bc3c9b
Closes-Bug: #1794167