Fix disconnect

Author: Nickolay Savchenko

lib/src/main/java/ua/naiksoftware/stomp/StompClient.java

@@ -126,6 +126,7 @@ public void connect(@Nullable List<StompHeader> _headers) {
 
                         case CLOSED:
                             Log.d(TAG, "Socket closed");
+                            getConnectionStream().onNext(false);
                             disconnect();
                             break;