Clean up handlePrefs method by removing comments

Removed commented-out code for preferences frame initialization.

Author: Stefterv

app/src/processing/app/Base.java

@@ -2191,10 +2191,6 @@ static private Mode findSketchMode(File folder, List<Mode> modeList) {
    * Show the Preferences window.
    */
   public void handlePrefs() {
-//    if (preferencesFrame == null) {
-//      preferencesFrame = new PreferencesFrame(this);
-//    }
-//    preferencesFrame.showFrame();
       PreferencesKt.show();
   }