Policy Server URL update does not trigger PTU

[renonick87]

It seems that the Manticore UI is sending the correct OnSystemRequest RPC to core to trigger a PTU when the URL is updated, but the PTU never reaches the Policy Server.

Reproduction steps:

1. Start the policy server and host through ngrok.
2. Open a manticore instance.
3. Specify the Policy Server URL in manticore to point to the ngrok instance and the correct policy endpoint.
4. Press the Update Policy Server URL button.

Expected result:

1. Manticore will give some visual indication that the URL was updated in core and the next connected app will trigger a PTU that gets sent to the Policy Server.

Actual result:

1. There's no indicator that pressing the button did anything. No errors are logged. The Policy Server never gets a request.

[jordynmackool]

@renonick87 found this to not be an issue, per the below:

1. In sdl_core v6.1.1 a change was made that had core not attempt a PTU if there were no apps connected. This might just be specific to a certain build of core. do not retry ptu if no apps are connected (#3350)
2. Since app policies for web apps are handled differently, the JS Suite is not built to handle the OnSystemRequest that core sends to initiate a PTU.
   When I found this issue I either had no apps connected or only a JS app. After updating a JS app to be able to handle the request, the PTU was able to complete it.