units: change Requires=systemd-networkd.service → BindsTo= one more time
Follow-up for da15f8406e9aeb7908e1d92c02d2ff5147c7788a which did the
change for systemd-networkd-wait-online.service, let's also do this for
systemd-networkd-wait-online@.service
(cherry picked from commit 51f3dc2234082c1ca9bdda403e4f355cab6be03b)