Ensure that dataWrapper feature is checked before using the 'data' value of a
reponse.

Reviewed: https://codereview.appspot.com/6737065/
Fixes: http://code.google.com/p/google-api-python-client/issues/detail?id=208
diff --git a/apiclient/model.py b/apiclient/model.py
index 0e31053..12fcab6 100644
--- a/apiclient/model.py
+++ b/apiclient/model.py
@@ -261,7 +261,7 @@
 
   def deserialize(self, content):
     body = simplejson.loads(content)
-    if isinstance(body, dict) and 'data' in body:
+    if self._data_wrapper and isinstance(body, dict) and 'data' in body:
       body = body['data']
     return body