fix: exit the program to trigger a restart when the gateway closes

src/main.rs

@@ -340,6 +340,10 @@ async fn handle_events(command_router: Arc<CommandRouter>, state: State, mut sha
             Ok(event) => {
                 handle_event(command_router.clone(), state.clone(), event).await;
             }
+            Err(twilight_gateway::error::Event::GatewayClose(frame_option)) => {
+                tracing::warn!(?frame_option);
+                return;
+            }
             Err(error) => {
                 tracing::error!(?error);
             }