Spanning tree protocol is enabled on bridges created by python-devops tests

[Eugene Korekin]

Spanning tree protocol is enabled on bridges created by python-devops tests.

devops/driver/libvirt/libvirt_xml_builder.py:

 46 network_xml.bridge(name="dobr{0}".format(network.id),
 47 stp="on", delay="0")

In some confugurations this may lead to forcible diconnection of server ports by switch(for example, on Cisco switches with BPDU guard feature on).

I propose to change this option to 'off' as it is more safe option, or make it configurable, at least.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/114760

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/114760
Committed: https://git.openstack.org/cgit/stackforge/fuel-devops/commit/?id=5453f6a0b11b5e2f92209cf0fbd195d98b439f47
Submitter: Jenkins
Branch: master

commit 5453f6a0b11b5e2f92209cf0fbd195d98b439f47
Author: Igor Shishkin <email address hidden>
Date: Sat Aug 16 19:11:19 2014 +0400

    Adding ability to turn on/off STP on bridges

    Change-Id: I54f9309b2bd99e01faab3aa0872d94e09ecda0c2
    Closes-Bug: #1355225