if JobScheduler starts without port configured in scheduler.xml this should be logged

Current Situation

• If JobScheduler is started without a port being configured in scheduler.xml then program starts but is not accessible by JOC as there is no port that JobScheduler is listening to.

Desired Behavior

• JobScheduler should log an error to scheduler.log if started without port configured

Resolution

• This issue should be covered by a future release that includes to replace the built-in HTTP server by Jetty, see JS-823