If a cluster operator has some tooling that makes directories in
/srv/node/<disk>/accounts, then the account replicator will treat
those directories as partition dirs and may remove empty
subdirectories contained therein. This wastes time and confuses the
operator.
This commit makes DB replicators skip partition directories whose
names don't look like positive integers. This doesn't completely avoid
the problem since an operator can still use an all-digit name, but it
will skip directories like "tmp21945".
Change-Id: I8d6682915a555f537fc0ce8c39c3d52c99ff3056
2bfd9c6a9b