livecheck: check throttle days before rate

When a `livecheck` block has a `throttle` call with both a numeric
rate and a `days` argument, the throttle days should be used as a
fallback when a new throttled version doesn't appear before the days
in the throttle interval have elapsed. That was the intention when the
throttle `days` option was added and it works for checks where there
aren't old throttled versions in the matches. However, for checks with
old throttled versions in the matches, `throttled_match_versions_map`
won't be blank and the fallback `days` logic won't be used.

This moves the throttle days conditional logic before the throttle
rate in the `if`/`elsif` setup, which will ensure that the days
throttle will be used if the interval has elapsed. If the throttle
interval hasn't elapsed, then the normal throttle rate checking
behavior will be used.