When running sysupgrade from an existing configuration, move existing
ipset definitions to a dedicated config section. Later on, it will allow
to server ipset as well as nftable sets from the same configuration.
Signed-off-by: Mathias Kresin <dev@kresin.me>
(cherry picked from commit 1b13190bee2b27875d70dcb44f0c95004bfe5227)