fix problem with python3 and extractor features

src/extraction/feature_extraction.py

@@ -173,7 +173,9 @@ class FeatureExtractor(object):
             raise IException("Image %s is possibly corrupt" % filepath)
 
         if len(self.data) > 0:
-            values = list(itertools.chain.from_iterable(zip(*([extractor().run(image)[2] for extractor in self.extractors]))))
+            labs, tys, values = [list(itertools.chain.from_iterable(ret))
+                                               for ret in
+                                               zip(*(extractor().run(image) for extractor in self.extractors))]
 	    
             self.data.append(values + [cl if cl in classes else classes[0]])