redpine: allow network namespaces

To test:

ip netns add testns;
read phy < /sys/class/net/wlan0/phy80211/name;
iw phy "$phy" set netns name testns;

Now wlan0 should disappear from default network namespace and should appear in testns:

ip -netns testns link show;

Delete testns to move phy back:

ip netns del testns;