fixed opengl errors

headers/Mandelbrot.h

@@ -2,9 +2,9 @@
 #pragma once
 
 #include <QVector2D>
-#include <QOpenGLFunctions_3_3_Core>
+#include <QOpenGLExtraFunctions>
 
-class Mandelbrot : public QObject, protected QOpenGLFunctions_3_3_Core {
+class Mandelbrot : public QObject, protected QOpenGLExtraFunctions {
 Q_OBJECT
 public:
 	void init();

headers/OutputWidget.h

@@ -6,7 +6,7 @@
 #include <QOpenGLWidget>
 #include "Mandelbrot.h"
 
-class OutputWidget : public QOpenGLWidget, protected QOpenGLFunctions_3_3_Core {
+class OutputWidget : public QOpenGLWidget, protected QOpenGLExtraFunctions {
 	Q_OBJECT
 public:
 	explicit OutputWidget(QWidget* parent): QOpenGLWidget(parent) {}