"Acquiring DHCP" forever when connecting to a network that uses udhcpd

`full_ap_demo_debug` and `list_access_points` stop at "Acquiring DHCP" and never time out. `connection` and `get_website{,_ssl,_libcurl}` just hang after saying they're connecting to Wi-Fi. I spent a long time trying to debug this because I thought the same problems were occurring with dnsmasq, but it's limited to udhcpd.