Added simple error hangling to 'SnakeTimer#broadcast'

In some cases the websocket communication fails and Snake#sendMessage throws an exception.
In that case the send loop is interrupted and later clients are not update.

spring-boot-samples/spring-boot-sample-websocket/src/main/java/org/springframework/boot/samples/websocket/snake/SnakeTimer.java

@@ -79,8 +79,13 @@ public class SnakeTimer {
 
     public static void broadcast(String message) throws Exception {
         for (Snake snake : SnakeTimer.getSnakes()) {
+			try {
 				snake.sendMessage(message);
 			}
+			catch (Throwable ex) {
+				// if Snake#sendMessage fails the client should be removed
+			}
+		}
     }