failover: Default to enabling SQL strategy
Given the SQL strategy is a reasonable default, and tested well enough,
this change makes the SQL strategy the preferred strategy. This was
local
, which creates dataloss scenarios when multiple Praefects are
behind a load balancer.
Additionally, this changes behaviour around the read only feature. This would default to being enabled. Currently availability is favoured over consistency. Now this is flipped.
Fixes: #2682 (closed)