Unlimited token generation - Wrong expiration time is shown

Steps to reproduce

• set the knox.token.ttl to -1 in the homepage topology for the KNOXTOKEN service
• set knox.token.lifespan.input.enabled = false in the homepage topology for the KNOXTOKEN service

Actual results

With KNOX-3017 in place, the token is generated, but the expiration is wrong, see attached screenshots.
In addition to this UI bug, the background reaper thread removes this token the next time it's triggered. This is also incorrect: unlimited tokens should never be removed automatically as they never expire.

Expected result

Token expiration should indicate an unlimited lifespan and unlimited tokens should not be revoked automatically.