Rsqrt support

I got an error below when converting a tensorflow frozen model to RKNN. It seems Rsqrt doesn't support it RKNN

I build output layer attach_embeddingsut0
I build input layer input:in0
D Try match Mul embeddings
I Match multiply [['embeddings']] [['Mul']] to [['multiply']]
D Try match Rsqrt embeddings/Rsqrt
W Not match node embeddings/Rsqrt Rsqrt
E Catch exception when loading tensorflow model: ./junk.pb!
T Traceback (most recent call last):
T   File "rknn/api/rknn_base.py", line 180, in rknn.api.rknn_base.RKNNBase.load_tensorflow
T   File "rknn/base/RKNNlib/converter/convert_tf.py", line 565, in rknn.base.RKNNlib.converter.convert_tf.convert_tf.match_paragraph_and_param
T   File "rknn/base/RKNNlib/converter/convert_tf.py", line 464, in rknn.base.RKNNlib.converter.convert_tf.convert_tf._tf_push_ready_node
T TypeError: 'NoneType' object is not iterable
done
--> Building model
2019-03-29 13:23:21.741608: I tensorflow/core/platform/cpu_feature_guard.cc:141] Your CPU supports instructions that this TensorFlow binary was not compiled to use: AVX2 FMA
E Catch exception when building RKNN model!
T Traceback (most recent call last):
T   File "rknn/api/rknn_base.py", line 459, in rknn.api.rknn_base.RKNNBase.build
T   File "rknn/api/rknn_base.py", line 939, in rknn.api.rknn_base.RKNNBase._quantize
T   File "rknn/base/RKNNlib/console/utils.py", line 7, in rknn.base.RKNNlib.console.utils.get_model_data_file
T   File "/usr/lib/python3.5/posixpath.py", line 122, in splitext
T     return genericpath._splitext(p, sep, None, extsep)
T   File "/usr/lib/python3.5/genericpath.py", line 118, in _splitext
T     sepIndex = p.rfind(sep)
T AttributeError: 'NoneType' object has no attribute 'rfind'
done
E RKNN model data is None, please load model first!