Apparently unmanaged devices are loaded only from main
NetworkManager.conf. Exactly the same line pasted (not typed!) to main
NetworkManager.conf works, but in
/etc/NetworkManager/conf.d/30-qubes.conf it doesn't.
BTW There was a typo in option name ("unmanaged_devices" instead of
"unmanaged-devices", but it wasn't the cause).
This reverts commit 6c4831339c.
QubesOS/qubes-issues#1176
Do not modify main /etc/NetworkManager/NetworkManager.conf as it would
cause conflicts during updates. Use
/etc/NetworkManager/conf.d/30-qubes.conf instead.
Also remove some dead code for dynamically generated parts (no longer
required to "blacklist" eth0 in VMs - we have proper connection
generated for it). It was commented out for some time already
FixesQubesOS/qubes-issues#1176
In FC15, NetworkManager by default uses global connections ("Available to all users"). Save them in /rw instead of /etc, to preserve them across reboots.
