Needs to add firewall_driver configuration to Linuxbridge plugin ini

[Akihiro Motoki]

firewall_driver has been introduced in the patch of OVS security group support and it affects Linux Bridge plugin.
The default value of firewall_driver is NoopDriver, so firewall_driver configuration is required in Linux Bridge plugin ini too.
The following needs to be added.
-----
[SECURITYGROUP]
# Firewall driver for realizing quantum security group function
firewall_driver = quantum.agent.linux.iptables_firewall.IptablesFirewallDriver
-----

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/21630

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/21630
Committed: http://github.com/openstack/quantum/commit/be71c828fb3f896958bc66b825a608d4f7a2aac9
Submitter: Jenkins
Branch: master

commit be71c828fb3f896958bc66b825a608d4f7a2aac9
Author: Akihiro MOTOKI <email address hidden>
Date: Mon Feb 11 18:26:40 2013 +0900

    Add firewall_driver option to linuxbridge_conf.ini

    Fixes bug 1121855

    firewall_driver configuration option has been introduced in the patch
    of OVS security group support and it affects Linux Bridge plugin.
    The default value of firewall_driver is NoopDriver.
    Thus firewall_driver configuration is required in Linux Bridge plugin.

    Change-Id: I403be91b01eb6fa679dab28cd4995c85d12100b9