manager: unmanage software devices when networking gets disabled

If a user disables networking, we consider that as an indication that
also software devices must be disconnected. OTOH, we don't want to
destroy them for external events as a system suspend.
12 jobs for bg/sw-device-sleep-rh1701585 in 48 minutes and 47 seconds (queued for 2 minutes and 22 seconds)
latest
Status Job ID Name Coverage
  Test
passed #257609
allowed to fail
checkpatch

00:01:20

passed #257616
t_debian:9

00:33:39

passed #257618
t_debian:sid

00:16:07

manual #257617
allowed to fail manual
t_debian:testing
passed #257610
t_fedora:28

00:25:40

passed #257611
t_fedora:29

00:33:37

failed #257612
t_fedora:30

00:00:29

manual #257613
allowed to fail manual
t_fedora:rawhide
passed #257614
t_ubuntu:16.04

00:16:09

passed #257615
t_ubuntu:18.04

00:17:18

 
  External
failed NetworkManager test verification

failed NetworkManager test verification

06:06:32

 
Name Stage Failure
failed
t_fedora:30 Test
$ date '+%Y%m%d-%H%M%S'; NM_INSTALL="dnf install -y" ./contrib/fedora/REQUIRED_PACKAGES
20190423-163753
Fedora Modular 30 - x86_64 3.0 MB/s | 2.1 MB 00:00
Fedora Modular 30 - x86_64 - Updates 317 B/s | 257 B 00:00
Fedora Modular 30 - x86_64 - Test Updates 3.1 MB/s | 2.9 MB 00:00
Fedora 30 - x86_64 - Test Updates 16 MB/s | 16 MB 00:01
Fedora 30 - x86_64 - Updates 468 B/s | 257 B 00:00
./contrib/fedora/REQUIRED_PACKAGES: line 13: 11 Segmentation fault (core dumped) $NM_INSTALL "$@"
ERROR: Job failed: exit code 1