modules: update LEDE

6b6578feec wireguard: version bump to 0.0.20171101
9740523763 ar71xx: fix LED config for DIR-869 A1
bdf19eec35 ipq806x: nbg6817: sync MAC addresses to the upstream values
2aff2add31 ipq806x: nbg6817: add kmod-fs-ext4 to device packages
63f6408ccc uclient: update to the latest version, fixes fetch of multiple files