GitLab

Look for wireless devices in /proc/net/wireless (legacy code), then
under /sys/class/net (sometimes slow to provide info), via ubus
(fix #481) and also get the configured devices in /etc/config/wireless.

This should finally make rescue IPv4 addresses stop appearing in br-lan.
Signed-off-by: Roger Pueyo Centelles <roger.pueyo@guifi.net>