message: Change grad of SoftPlus to use the sigmoid function which works better for higher order gradients.
diff: @@ -465,7 +465,7 @@ def _SeluGrad(op, grad):
  @ops.RegisterGradient("Softplus")
  def _SoftplusGrad(op, grad):
  - return gen_nn_ops.softplus_grad(grad, op.inputs[0])
  + return grad * math_ops.sigmoid(op.inputs[0])
  @ops.RegisterGradient("SoftplusGrad")
  