ConnectionWatchdog should handle timer's IllegalStateException properly

redisson/src/main/java/org/redisson/client/handler/ConnectionWatchdog.java

@@ -82,12 +82,16 @@ public class ConnectionWatchdog extends ChannelInboundHandlerAdapter {
             return;
         }
         
+        try {
             timer.newTimeout(new TimerTask() {
                 @Override
                 public void run(Timeout timeout) throws Exception {
                     tryReconnect(connection, Math.min(BACKOFF_CAP, attempts + 1));
                 }
             }, timeout, TimeUnit.MILLISECONDS);
+        } catch (IllegalStateException e) {
+            // skip
+        }
     }
 
     private void tryReconnect(final RedisConnection connection, final int nextAttempt) {