Failed convert for LookupTableExportV2

[strgrb]

tensorflow-onnx/tf2onnx/tf_loader.py

Line 317 in 47acb8a

logger.warning("Could not initialize table with shared_name = %r", n)

在这一行报错，变量n没有定义

[TomWildenhain-Microsoft]

Thanks. #1709 should fix the error.