modules: update OpenWrt packages

476b8b82b Merge pull request #15806 from blocktrron/pr-xr-usb-serial-1907
73c098477 xr_usb_serial_common: add PKG_MIRROR_HASH
7100f4006 xr_usb_serial_common: fix build
465ddb5b2 Merge pull request #15770 from DeathCamel58/libnet-1.2.x-libnet-config-fix
f7d4a6753 Merge pull request #15780 from stangri/19.07-https-dns-proxy
6ab17abde https-dns-proxy: update to 2021-06-03-1
bdbf33f69 libnet: Export `libnet-config` in development enviornments

Signed-off-by: David Bauer <mail@david-bauer.net>