docker_: Plugin fails for cpu, memory and networking when a container is in restart loop

[NITEMAN]

The traces looks like:

# munin-run docker_cpu
...
Traceback (most recent call last):
  File "/etc/munin/plugins/docker_cpu", line 474, in <module>
    main()
  File "/etc/munin/plugins/docker_cpu", line 433, in main
    print_containers_cpu(client)
  File "/etc/munin/plugins/docker_cpu", line 268, in print_containers_cpu
    system_delta = (float(stats["cpu_stats"]["system_cpu_usage"])
KeyError: 'system_cpu_usage'

# munin-run docker_memory
...
Traceback (most recent call last):
  File "/etc/munin/plugins/docker_memory", line 474, in <module>
    main()
  File "/etc/munin/plugins/docker_memory", line 447, in main
    print_containers_memory(client)
  File "/etc/munin/plugins/docker_memory", line 278, in print_containers_memory
    print(container.name + '.value', stats['memory_stats']['stats']['total_rss'])
KeyError: 'stats'

# munin-run docker_network
...
Traceback (most recent call last):
  File "/etc/munin/plugins/docker_network", line 474, in <module>
    main()
  File "/etc/munin/plugins/docker_network", line 470, in main
    print_containers_network(client)
  File "/etc/munin/plugins/docker_network", line 286, in print_containers_network
    for data in stats['networks'].values():
KeyError: 'networks'