Fix format errors in nova security group rule list

* port range was throwing exception for None to/from ports
* ip_range didn't always have cidr causing error
* ip_protocol None at times and looked bad

Closes-Bug #1256935

Change-Id: I451a0f038a3e9646bca3f278c5d6f6d7e3097a83
Merge "Fix format errors in nova security group rule list"