Fixes android-async-http#716

Author: smarek

library/src/main/java/com/loopj/android/http/DataAsyncHttpResponseHandler.java

@@ -30,7 +30,7 @@
 public abstract class DataAsyncHttpResponseHandler extends AsyncHttpResponseHandler {
     private static final String LOG_TAG = "DataAsyncHttpResponseHandler";
 
-    protected static final int PROGRESS_DATA_MESSAGE = 6;
+    protected static final int PROGRESS_DATA_MESSAGE = 7;
 
     /**
      * Creates a new AsyncHttpResponseHandler