Use the same Ruby version for deployment as you're running locally

This avoids issues with patchlevels I was having. It also means that
when we upgrade the Ruby version in `.ruby-version` then you should
start deploying with that version too.
Don't auto-reload scraper config in the PlanningAlerts app any more

This was causing issues where a scraper URL had been updated in the
PlanningAlerts web admin interface. The Lake Mac scraper had been
deprecated in favour of a council supplied XML feed but when this
code was deployed it overwrote the updated and correct new feed URL.