compatible with engine.io-client 1.2.2

src/main/java/com/github/nkzawa/engineio/client/Socket.java

@@ -458,6 +458,8 @@ public class Socket extends Emitter {
         this.pingInterval = data.pingInterval;
         this.pingTimeout = data.pingTimeout;
         this.onOpen();
+        // In case open handler closes socket
+        if (ReadyState.CLOSED == this.readyState) return;
         this.setPing();
 
         this.off(EVENT_HEARTBEAT, this.onHeartbeatAsListener);