fix exp_main import bug

Author: MAZiqing

exp/exp_main.py

@@ -1,7 +1,6 @@
 from data_provider.data_factory import data_provider
 from exp.exp_basic import Exp_Basic
-from models import Informer, FEDformer, Transformer, Logformer, Reformer,Transformer_sin,Autoformer_sin
-# from models.reformer_pytorch.reformer_pytorch import Reformer
+from models import Informer, FEDformer, Transformer
 from utils.tools import EarlyStopping, adjust_learning_rate, visual
 from utils.metrics import metric