api_address output uses internal loadbalancer ip in case of floating ips disabled in template

[SFilatov]

Here's the case:
I create cluster template with master_lb enabled and floating ips disabled.
I expect that I'm going to use master_lb floating ip to work with api server. I dont need to connect to my nodes and dont want to waste floating ip on them - disable floating_ip for my cluster template.

api_address_floating_switch takes into account that I have floating ips disabled and outputs lb's private ip - which magnum uses as api_address later on.
That causes all magnum-conductor - k8s interactions to fails since there's no connection between magnum conductor and user's private network