[bug 987471] close_old_connections() before updating metrics

Our DB load balancer closes connections after 5 minutes. Our cron
jobs that talk to google analytics, take a lot more than that. So
we now close the connections before updating the database with
fresh data from google analytics. This means new connections are
opened and all is good.

I'm not sure if all that above is exactly correct. BUT, I tried this on
stage and it solves the symptoms.

I don't know of a way to test this locally, so I propose we ship and
test in prod when it runs overnight. Unless there is something
horrible about it.

r?