Add iptables rule for Ironic VMs -> Swift

The agent ramdisk gets instance images from swift, set firewall
rules to allow this.

Also configure Ironic API port using the correct variable, and
use SWIFT_DEFAULT_BIND_PORT for Swift ports everywhere.

Change-Id: Ieec8cc64e504b04a21daa49e90e2d4925f4838ee
Merge "Add iptables rule for Ironic VMs -> Swift"