ApiExecutor for JITL Jobs should try all URLs for the JS7 REST Web Service API in case of connection issues

Current Situation

• For JITL Jobs the ./config/private/private.conf file can hold a number of URLs of Primary and Secondary JOC Cockpit instances providing the JS7 REST Web Service API.
• Currently only the first URL from the list of URLs in the private.conf file is used to establish a connection to the JS7 REST Web Service APIs.

Desired Behavior
The API executor should try all URIs from the array one after the other until a connection can be established or none of the given URLs can be reached.