Remove invalid comment.

No point in making this protected: it breaks existing code including
the unit tests, and the base class has this method as public.

Task-number: QTBUG-23524
Change-Id: I8fae019088fc368213ff7caa4b19fe7ab60488dd
Reviewed-by: Jonas Gastal <jgastal@profusion.mobi>
Reviewed-by: Robin Burchell <robin+qt@viroteck.net>

src/widgets/dialogs/qinputdialog.h

@@ -201,9 +201,8 @@ Q_SIGNALS:
     void doubleValueChanged(double value);
     void doubleValueSelected(double value);
 
-
 public:
-    void done(int result); // ### Qt 5: Make protected.
+    void done(int result);
 
 private:
     Q_DISABLE_COPY(QInputDialog)