Current code assumes that if Node is removed from the list on `UpdateLoadBalancer()`, we don't care about it's SG. The Node's port will be gone or if not we'll be able to find it later on by querying ports with the SG tag. This works, but can be improved.

The idea here is for `applyNodeSecurityGroupIDForLB()` to also lookup ports that have the SG tag and detach the SG from the ports that aren't belonging to the ports of the current list of Nodes.