Security group OVO object don't reloads and make compatible rules objects

[Slawek Kaplonski]

SecurityGroup OVO object don't reload and make compatible requested SecurityGroupRule objects which belongs to the SecurityGroup.
Becuase of that if e.g. neutron-ovs-agent is requesting SecurityGroup with SecurityGroupRules in version e.g. 1.0, neutron server will return SecurityGroup with rules in the latest version.

Until now, it isn't a problem as we have only version 1.0 of both SecurityGroup and SecurityGroupRule but this affects patches like https://review.opendev.org/#/c/749158/ and https://review.opendev.org/#/c/751110/ which bumps version of the SecurityGroupRule and that is causing failures in the grenade jobs.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/762434