Resync RasterizerDummy to Rasterizer

drivers/dummy/rasterizer_dummy.h

@@ -831,6 +831,8 @@ public:
 
 	virtual bool is_low_end() const { return true; }
 
+	virtual const char *gl_check_for_error(bool p_print_error = true) { return nullptr; }
+
 	RasterizerDummy() {}
 	~RasterizerDummy() {}
 };