message: set_shape fix in _UnreadVariable
diff: @@ -933,6 +933,9 @@ class _UnreadVariable(ResourceVariable):
  return gen_resource_variable_ops.read_variable_op(self._handle,
  self._dtype)
  + def set_shape(self, shape):
  + self._shape = shape
  +
  @property
  def op(self):
  """The op for this variable."""
  