Make ControlFlow::Wait the default (#3106)

examples/mouse_wheel.rs

@@ -3,7 +3,7 @@
 use simple_logger::SimpleLogger;
 use winit::{
     event::{Event, WindowEvent},
-    event_loop::{ControlFlow, EventLoop},
+    event_loop::EventLoop,
     window::WindowBuilder,
 };
 
@@ -35,8 +35,6 @@ In other words, the deltas indicate the direction in which to move the content (
     );
 
     event_loop.run(move |event, elwt| {
-        elwt.set_control_flow(ControlFlow::Wait);
-
         if let Event::WindowEvent { event, .. } = event {
             match event {
                 WindowEvent::CloseRequested => elwt.exit(),