gui2/tcustom_tod: Avoid having display::draw() commit the framebuffer

This allows the dialog to be redrawn on top of the updated display
contents once we are done without any flickering, and performance is
much better because this results in the framebuffer being committed once
instead of twice every time ToD color shift slider events are processed.

src/gui/dialogs/editor/custom_tod.cpp

@@ -206,7 +206,7 @@ void tcustom_tod::update_tod_display(twindow& window)
 	// invalidate all tiles so they are redrawn with the new ToD tint next
 	display_->invalidate_all();
 	// redraw tiles
-	display_->draw();
+	display_->draw(false);
 
 	window.invalidate_layout();
 }