[Win] Move recoverDefaultSketchbookFolder after init() stage

Solves #7097; the user will be prompted if default sketchbook folder doesn't exist.
If needed, the exception will be thrown by getDefaultSketchbookFolder() as in Linux/OSX implementations.

Author: facchinm

arduino-core/src/processing/app/windows/Platform.java

@@ -44,15 +44,14 @@
 public class Platform extends processing.app.Platform {
 
   private File settingsFolder;
-  private File defaultSketchbookFolder;
+  private File defaultSketchbookFolder = null;
 
   @Override
   public void init() throws Exception {
     super.init();
 
     checkPath();
     recoverSettingsFolderPath();
-    recoverDefaultSketchbookFolder();
   }
 
   private void recoverSettingsFolderPath() throws Exception {
@@ -119,6 +118,7 @@ public File getSettingsFolder() {
 
   @Override
   public File getDefaultSketchbookFolder() throws Exception {
+    recoverDefaultSketchbookFolder();
     return defaultSketchbookFolder;
   }