fixing build for predict

predict.py

@@ -104,13 +104,13 @@ def run(args, field, val_sets, model):
         if not os.path.exists(prediction_file_name):
             with open(prediction_file_name, 'a') as prediction_file:
                 predictions = []
+                wikisql_ids = []
                 for batch_idx, batch in enumerate(it):
                     _, p = model(batch)
                     p = field.reverse(p)
                     for i, pp in enumerate(p):
                         if 'sql' in task:
                             wikisql_id = int(batch.wikisql_id[i])
-                            wikisql_ids = wikisql_ids if wikisql_ids is not None else []
                             wikisql_ids.append(wikisql_id)
                         prediction_file.write(pp + '\n')
                         predictions.append(pp)