specify allowed origin

src/main/java/fr/jaquin/bdlg/planner/websockets/WebSocketConfig.java

@@ -18,7 +18,8 @@ public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
 
   @Override
   public void registerStompEndpoints(final StompEndpointRegistry registry) {
-    registry.addEndpoint("/ws").withSockJS();
+    registry.addEndpoint("/ws")
+        .setAllowedOrigins("https://bdlg-planner.jaquin.fr/*", "http://localhost/*").withSockJS();
   }
 
 }