rc.d/zpool should require (rw) root?

From: Andriy Gapon <avg_at_FreeBSD.org>
Date: Fri, 04 Feb 2022 10:07:04 UTC
It seems that in some cases zpool import -c requires read/write access to the 
zpool.cache file.  So, it probably makes sense to import "other" pools 
(non-root) after upgrading / to rw.
What do you think?

-- 
Andriy Gapon