Use default cidr to avoid exception when editing quantum security rules.

$ quantum security-group-rule-create --direction ingress --protocol TCP
--port-range-min 80 --port-range-max 80 web

After creating security group rule with command above, An exception is thrown
when editing the rules for groups web.

Fixes: bug #1165095

Change-Id: If32992622ebc20559dde911455b241937eb59ae6
Merge "Use default cidr to avoid exception when editing quantum security rules."