As the openstack platform is migrating to the external cloud provider, the user-managed cloud.conf in `openshift-config/cloud-provider-config` is now the source for both the in-tree cloud.conf (in `openshift-config-managed/kube-cloud-config`) and the CCM cloud.conf (in `openshift-cloud-controller-manager/cloud-conf`).

However, even after switching to CCM we need to keep initializing the in-tree cloud provider in order to be able to detach volumes created with legacy cloud provider.

Moreover, the legacy cloud provider errors out when it finds an option it does not understand, causing KCM to enters a crashloopback.

We can't legitimately ask customer to limit themselves to the intersection of in-tree and external cloud provider options. We should make the legacy cloud provider option parsing more tolerant and ignore unknown options.