Backport 2 commits to fix build on 4.19:
3ea761a1ed
2b76b68c65

Signed-off-by: Deng Qingfang <dengqf6@mail2.sysu.edu.cn>

This commit moves xtables-addons from
https://github.com/openwrt/openwrt/tree/master/package/network/utils/xtables-addons
into the package feed repository to allow for dependencies on other feed
packages, such as Perl.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
[fix commit message]
Signed-off-by: Jo-Philipp Wich <jo@mein.io>

Signed-off-by: Jo-Philipp Wich <jo@mein.io>