post-receive-move-tmp-refs: adapt for NoteDb replication
post-receive-move-tmp-refs: adapt for NoteDb replication

The hook required oldrev to be NULL_SHA1, that the update was a
creation, but NoteDb refs, $CHANGE_REF/meta, can also be updated.
This would cause NoteDb to be stale on the mirror since the
post-receive hook would only be run for the initial creation of
the ref and not for updates.

Add suggestion to add refs/meta/* to refspecs.

Change-Id: I8e2612880e7c67b0b9281e73d9880484fdf4d056

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