title: Tensorflow fails to load RNN from checkpoint after update
body: <p>After updating tensorflow to the latest version, my checkpoint fails to load from disk. I get an error that looks like this:</p>
  
  <pre><code>...
   File "/usr/lib/python2.7/site-packages/tensorflow/python/training/saver.py", line 1560, in restore
      {self.saver_def.filename_tensor_name: save_path})
    File "/usr/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 895, in run
      run_metadata_ptr)
    File "/usr/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 1124, in _run
      feed_dict_tensor, options, run_metadata)
    File "/usr/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 1321, in _do_run
      options, run_metadata)
    File "/usr/lib/python2.7/site-packages/tensorflow/python/client/session.py", line 1340, in _do_call
      raise type(e)(node_def, op, message)
  tensorflow.python.framework.errors_impl.NotFoundError: Key model/rnn/multi_rnn_cell/cell_0/lstm_cell/kernel not found in checkpoint
       [[Node: model/save/RestoreV2_4 = RestoreV2[dtypes=[DT_FLOAT], _device="/job:localhost/replica:0/task:0/cpu:0"](_arg_model/save/Const_0_0, model/save/RestoreV2_4/tensor_names, model/save/RestoreV2_4/shape_and_slices)]]
  </code></pre>