It only makes sense to start unudhcpd when a UDC exists, to prevent unudhcpd starting when there's e.g. only a physical ethernet device. Fixes #4802 Signed-off-by: Clayton Craft <craftyguy@postmarketos.org> Part-of: <https://gitlab.postmarketos.org/postmarketOS/pmaports/-/merge_requests/9243>