optimizer update

Author: Lingjun Liu

tensorlayer/models/transformer/utils/optimizer.py

@@ -23,7 +23,7 @@
 K = tf.keras.backend
 
 
-class LazyAdam(tf.keras.optimizers.Adam):
+class LazyAdam(tf.optimizers.Adam):
     """Variant of the Adam optimizer that handles sparse updates more efficiently.
 
   The original Adam algorithm maintains two moving-average accumulators for