restartOnExternalChanges for appsettings

1. If you want to do this, you will have to change it in machine.config. By default, it is specified as true in machine.config.

2. If the appsettings are stored in external file like mySettings.config, then any changes to mySettings.config will not get effected if you specify appsettings "file" attribute. But if you specify "configSource" attribute, it is effected immediately.