policy matching: fix: ignored classes overiden by policy classes.

Files matching an 'ignored' class appeared as matching a policy case
in the DB. This had no major impact as the whitelist condition
was tested against when applying the policy, but the class reporting was wrong.
migration stats: fixed wrong volume display is stats.

The displayed volume of migrated data included skipped files.
incr version to 2.4.3-3
changelog reader: reopen changelog when getting EPROTO or EINVAL error.

When getting EPROTO error from llapi_changelog_recv(), robinhood
was continuing its read loop and continuously got EPROTO
for next records. This basically occured after a client eviction.
With this patch, robinhood now reopens the changelog in this case,
to be resilient to such situation.
Do the same for EINVAL to be resilient with umount/mount.