add scaling check to troubleshooting section

[ibmrcruicks]

in the Why does my app stop? setion, consider adding a simple check for scaling settings, as the app can be shutdown while there is nothing wrong with it.

Because you have configured it with scaling factor min=0 -- when the app is observed to be idle, it will be scaled down to zero; there will be no instance running, and health-checks may report timeouts for the application