Convert conntrack command properly when firewall rule has port range

[Vu Cong Tuan]

Current code only converts conntrack command from firewall rule properly
if the firewall rule contains only single port like:

`neutron firewall-rule-create --protocol tcp --action allow --ip-version
4 --destination-port 8777 --enabled True`

However, if the rule contains port range, which is possible when
creating firewall rule like this:

`neutron firewall-rule-create --protocol tcp --action allow --ip-version
4 --destination-port 8778:9000 --enabled True`

The conntrack command would look like:

['ip', 'netns', 'exec', 'qrouter-7bab1e53-0330-41af-8e98-b925d1a76984',
'conntrack', '-D', '-p', 'tcp', '-f', 'ipv4', '--dport', '8778:9000']

Conntrack-tools does not understand the option `--dport 8778:9000`, it
instead applies above command to port 8778 only, which is not expected.

This Patch Set fixes that issue by following the same method in
netlink implementation [1]

[1] https://review.openstack.org/#/c/438445/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/443385
Committed: https://git.openstack.org/cgit/openstack/neutron-fwaas/commit/?id=f589293aeca733501fa7cab0268dd8440e19ebf5
Submitter: Jenkins
Branch: master

commit f589293aeca733501fa7cab0268dd8440e19ebf5
Author: Cuong Nguyen <email address hidden>
Date: Thu Mar 9 09:14:14 2017 +0700

    FW rule applied incorrectly if port specified is a range

    When creating a firewall rule with port specified as a range of values,
    e.g. [1], conntrack command for deleting current conntrack entries is
    applied to the first number in the range, e.g. port #8778 in [1],
    instead of the range of ports 8778:9000.

    This incorrect behavior occurs because conntrack-tools
    does not understand the port as a range of values.
    This patch set fixes that issue by following the same method as done
    in the netlink implementation in [2].

    [1] "neutron firewall-rule-create --protocol tcp --action allow
    --ip-version 4 --destination-port 8778:9000 --enabled True"
    [2] https://review.openstack.org/#/c/438445/

    Closes-Bug: #1702242
    Co-Authored-By: Vu Cong Tuan <email address hidden>
    Change-Id: Ib17db09069a07f35109357d20b67b1acfa85c1a4

[OpenStack Infra (hudson-openstack)]

This issue was fixed in the openstack/neutron-fwaas 12.0.0.0b1 development milestone.