Vincent Demeester df30b2fb86 Do not panic if network is nil ...

network is `nil` if the following case:

```
services:
  foo:
    image: nginx
    networks:
      mynetwork:
```

It's a valid compose so we should not panic.

Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Upstream-commit: 2638cd6f3d
Component: cli

2016-11-21 17:59:29 +01:00

..

cli

Do not panic if network is nil

2016-11-21 17:59:29 +01:00