SSL context atrribute is not marked as required even though it is

When adding new HTTPS listener using the Web Console, user is not able to do so without specifying ssl-context attribute which is not marked as required despite that it is.

Following is the output from CLI:

/subsystem=undertow/server=default-server/https-listener=aaa:add(socket-binding=management-https)
{
    "outcome" => "failed",
    "failure-description" => "WFLYCTL0172: ssl-context is required",
    "rolled-back" => true
}

Steps to reproduce:
1. Go to the HTTP server configuration page via Subsystem -> Web/HTTP - Undertow -> HTTP -> HTTP Server tab
2. Click 'View' on any of your servers
3. Click 'HTTPS Listener' tab -> 'Add'
4. Fill in attributes marked as required and click 'Save'