fix koush#245 on socket.io reconnect, update the connecting field with the current Cancellable

Ensure calls to SocketIOConnection.reconnect() when a reconnect attempt is already is progress will properly have their DependentCancellables made children of that attempt.

Author: justinwh

AndroidAsync/src/com/koushikdutta/async/http/socketio/SocketIOConnection.java

@@ -104,7 +104,7 @@ void reconnect(final DependentCancellable child) {
 
         request.logi("Reconnecting socket.io");
 
-        Cancellable connecting = httpClient.executeString(request, null)
+        connecting = httpClient.executeString(request, null)
         .then(new TransformFuture<SocketIOTransport, String>() {
             @Override
             protected void transform(String result) throws Exception {