Fix naming collissions in OpenIDC token refresh
    
    Without this, refreshing a token would fail because token would
    become a string, overwriting the dict that was there before, while
    we still need to use parts of the dict later on.
    
    Signed-off-by: Patrick Uiterwijk <puiterwijk@redhat.com>
    Reviewed-by: Pierre-Yves Chibon <pingou@pingoured.fr>