lxd/db/cluster/update: Fix upgrade from 2.0/3.0 when using go-dqlite v1.10.1 NULLable fields
lxd/db/cluster/update: Fix upgrade from 2.0/3.0 when using go-dqlite v1.10.1 NULLable fields

Signed-off-by: Thomas Parrott <6b778ce645fb0e3dde76d79eccad490955b1ae74@canonical.com>

stgraber/lxd,stgraber/lxd,lxc/lxd,stgraber/lxd,lxc/lxd,lxc/lxd,stgraber/lxd,stgraber/lxd,hallyn/lxd,hallyn/lxd,lxc/lxd,hallyn/lxd,hallyn/lxd,stgraber/lxd,hallyn/lxd,lxc/lxd,hallyn/lxd,lxc/lxd,stgraber/lxd,lxc/lxd