What does this PR do ?

fix bug #111

Before your PR is "Ready for review"

Pre checks:

[x] Have you signed your commits? Use git commit -s to sign.
[x] Do all unittests finish successfully before sending PR? 1) pytest or (if your machine does not have GPU) pytest --cpu from the root folder (given you marked your test cases accordingly @pytest.mark.run_only_on('CPU')). 2) Sparrowhawk tests bash tools/text_processing_deployment/export_grammars.sh --MODE=test ...
[ ] If you are adding a new feature: Have you added test cases for both pytest and Sparrowhawk here.
[ ] Have you added __init__.py for every folder and subfolder, including data folder which has .TSV files?
[ ] Have you followed codeQL results and removed unused variables and imports (report is at the bottom of the PR in github review box) ?
[ ] Have you added the correct license header Copyright (c) 2023, NVIDIA CORPORATION & AFFILIATES. All rights reserved. to all newly added Python files?
[ ] If you copied nemo_text_processing/text_normalization/en/graph_utils.py your header's second line should be Copyright 2015 and onwards Google, Inc.. See an example here.
[ ] Remove import guards (try import: ... except: ...) if not already done.
[ ] If you added a new language or a new feature please update the NeMo documentation (lives in different repo).
[ ] Have you added your language support to tools/text_processing_deployment/pynini_export.py.

PR Type:

If you haven't finished some of the above items you can still open "Draft" PR.