* core: declare "startup complete" when device reaches "connected"
 state, even if IP addressing methods did not yet fully complete.
 This changes behavior for unblocking "NetworkManager-wait-online.service",
 and "network-online.target" earlier. If this causes issues in your
 setup, you may need to configure "ipv4.may-fail=no" or "ipv6.may-fail=no",
 which delays reaching "connected" state for the address family accordingly.