shows 'Connection failed' when the connection works but the instance has no segments

Problem/Motivation

This code will cause the error to show if the connection works but returns no segments:

            '#description' => $client->segments()->listSegments() ? $this->t('Connection successfully established via @type!', ['@type' => $connector_id]) : $this->t('Connection failed, there was a problem with the connection to the UNOMI API instance.'),

That's misleading, as the problem doesn't lie with the admin configuration in Drupal but with the Unomi instance.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes