Do not update floating ip if its already mapped correct

[tobiasgiese]

/kind bug

What steps did you take and what happened: [A clear and concise description of what the bug is.]

We had problems reconciling our clusters with legacy load balancers, which were migrated from Neutron LBaaS to Octavia. The issue is that the port has no project id associated. Therefore, a floating ip association will fail with the error:

Bad floatingip request: Cannot process floating IP association with Port a52bde06-ea25-4264-85b9-3af36628109b, since that port is owned by a different tenant.

What did you expect to happen:

The floating ip shouldn't be handled at all if it's already mapped.

Anything else you would like to add: [Miscellaneous information that will assist in solving the issue.]

Environment:

• Cluster API Provider OpenStack version (Or git rev-parse HEAD if manually built): v0.4.0
• Cluster-API version: v0.4.0 (latest master)
• OpenStack version: VIO 7.0
• Minikube/KIND version:
• Kubernetes version (use kubectl version): v1.21.3
• OS (e.g. from /etc/os-release):

[hidekazuna]

I do not know the difference between Ocatavia load balancer migrated from Neutron LBaaS and new Octavia load balancer, but your expectation is reasonable.