OIDC auth token refresh doesn't fall back to re-auth if token has expired

Manifests as
```
[298180.888]    INFO sdk-golang/ziti.(*ContextImpl).RefreshApiSessionWithBackoff.func1: {error=[ErrorType=invalid_request Description=subject_token is invalid]} unable to refresh apiSession, error type *oidc.Error, will retry
```
Happens if the system is put to sleep long enough for the JWT to expire.