Fix oo-mongo-setup for cloud environments

- If oo-mongo-setup detects a cloud environment (local ip is not the
  same as resolved ip) then it will configure mongo to listen on 0.0.0.0
  instead of 127.0.0.1 and resolved ip
IIRC ifconfig output differs between EL6 and modern tools (Fedora, EL7) so I think ip is more reliable to parse.

Output from my local machine that wouldn't parse with the above line:
```
enp4s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1480
        inet 192.168.1.3  netmask 255.255.255.0  broadcast 192.168.1.255
```

I'd suggest:
```bash
ip addr show | awk '/inet / { print $2 }' | cut -d/ -f1
```