Update elasticsearch_backend.py

Author: frutik

haystack/backends/elasticsearch_backend.py

@@ -487,7 +487,7 @@ def search(self, query_string, **kwargs):
         try:
             raw_results = self.conn.search(body=search_kwargs,
                                            index=self.index_name,
-                                           doc_type='modelresult')
+                                           doc_type='modelresult', _source=True)
         except elasticsearch.TransportError as e:
             if not self.silently_fail:
                 raise