Standby replicas no longer need to use an idiosyncratic
journals.rep folder, and now use the same checkpoints dir
naming convention as edge servers and other replica types.
Back story: Prior to P4D 2018.1, standby replicas follow a
different convention for placement of journal files. With
the introduction of the rpl.journalcopy.location configurable
in P4D 2018.1, standby replicas now set that configurable and
use the same convention as other replica types.