openwrt: Fix typo in setting eui64 ip on LAN

As reported on our forum, there is a typo in the patch that is modifying
default IPv6 assignment for LAN network.

https://forum.turris.cz/t/turris-os-6-5-1-is-out/19722/15

patches/openwrt/to-upstream/0001-base-files-Better-IPv6-defaults.patch

@@ -23,7 +23,7 @@ index 38362813d1..a19b3ede79 100755
 +			if [ -e /proc/sys/net/ipv6 ]; then
 +				uci -q batch <<-EOF
 +					set network.$1.ip6assign='60'
-+					set network.$1.ip6ifaceif='eui64'
++					set network.$1.ip6ifaceid='eui64'
 +					set network.$1.ip6addr='fe80::1'
 +				EOF
 +			fi