Merge pull request #1242 from cuicheng01/release/2.2

[Cherry-pick]fix Alexnet lr bug

ppcls/configs/ImageNet/AlexNet/AlexNet.yaml

@@ -34,9 +34,8 @@ Optimizer:
   momentum: 0.9
   lr:
     name: Piecewise
-    learning_rate: 0.01
     decay_epochs: [30, 60, 90]
-    values: [0.1, 0.01, 0.001, 0.0001]
+    values: [0.01, 0.001, 0.0001, 0.00001]
   regularizer:
     name: 'L2'
     coeff: 0.0001