Cleanup Outscale API backoff

[jfbus]

The k8s backoff only backoffs when the backoff function returns false, nil.

The usual backoff from OAPI would be:

• no backoff on TCP errors,
• backoff on some HTTP errors (based on status code).

All CAPOSC OAPI calls use backoff the same way:

response, httpRes, err = oscApiClient.ApiCall()
if err != nil {
	if httpRes != nil {
		// does not trigger backoff
		return false, fmt.Errorf("error %w httpRes %s", err, httpRes.Status)
	}
	// httpRes is currently nil, only TCP errors without http response are left
	requestStr := fmt.Sprintf("%v", readImageRequest)
	if reconciler.KeepRetryWithError(
		requestStr,
		httpRes.StatusCode, // triggers a nil pointer exception ...
		reconciler.ThrottlingErrors) {
		// even if there was no nil pointer, will never be called as all http errors have already been handled
		return false, nil
	}
	return false, err
}
return true, err

There are two options:

• fix backoff
• remove backoff

As the cluster-api controller does backoff, backoff on CAPOSC side isn't really necessary.

Removing all backoff code would simplify things and would not change the way CAPOSC works.