Fixed the grand-central-cors middleware.

[goat-ssh]

Summary of changes

Switch the default case to accessControlAllowOriginListRegex: [".*"] when spec.cluster.settings.http.cors.allow-origin is not set (which might be the case on older clusters)

/account/organizations/21095b48-a276-46a7-95fd-64479f4d409d/projects/fc7ada71-5d28-4d49-8203-ff4649dbd13c/clusters/5e52d9b3-3b92-4568-a3a4-620ed9d1d445/monitoring/cluster:1 
Access to fetch at 'https://devbrain.gc.aks1.eastus2.azure.cratedb.net/api/health' from origin 'https://console.cratedb.cloud' has been blocked by CORS policy:
The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'.

Checklist

• Link to issue this PR refers to:
• Relevant changes are reflected in CHANGES.rst
• Added or changed code is covered by tests
• Documentation has been updated if necessary
• Changed code does not contain any breaking changes (or this is a major version change)