Remove cached console auth token after migration

After migrating to another server, the cached instance console auth
tokens become invalid, so we remove the tokens associated with the instance.

Fix bug #1214829

Co-authored-by: Takashi Natsume <natsume.takashi@lab.ntt.co.jp>
Change-Id: I7fddcd13da128a6bec5e2cdb6fa8c8636d6adb24
Merge "Remove cached console auth token after migration"