cache: better implemented changing disk cache folders

Not complete yet, but getting there.

app/core.cpp

@@ -177,10 +177,6 @@ void Core::DeclareTypesForQt()
 
 void Core::Start()
 {
-  // Reset config (Config sets to default on construction already, but we do it again here as a workaround that fixes
-  //               the fact that some of the config paths set by default rely on the app name having been set (in main())
-  Config::Current().SetDefaults();
-
   // Load application config
   Config::Load();