enable model test "resnet50_v2_nhwc"

Author: zhijxu-MS

tests/run_pretrained_models.yaml

@@ -239,7 +239,6 @@ resnet50_v2_nchw: # NOTE: Tensorflow 1.9.0 fails
 
 
 resnet50_v2_nhwc:
-  disabled: true # FIXME: numerical results are correct but shape=(64,) for tf and (64,1) for lotus
   model_type: saved_model
   url: http://download.tensorflow.org/models/official/20181001_resnet/savedmodels/resnet_v2_fp32_savedmodel_NHWC.tar.gz
   model: resnet_v2_fp32_savedmodel_NHWC/1538687283