This bug was discovered when lottery.check_if_end_lottery_task was
failing due to a stack trace thru end_lottery session < badge_grant
< send_repeatable_notifications < sanitize L208. In particular, when
`flask cron` (helpers/cron.py) executes, it does not set g.v, whereas
this code previously assumed that g.v : (None + User) and did not
check for its presence.