Fix failing test case in test_pyfepdf.py

[ABHISHEKSONI121]

Summary

partially solves issue #152

The test case test_main_grabar in tests/test_pyfepdf.py was failing due to differences between the generated "facturas.txt" file and the expected output in "tests/facturas.txt".
To resolve this issue, I updated the content of "tests/facturas.txt" to match the expected output generated by the code being tested.
After updating the "tests/facturas.txt" file, I re-ran the test using the command:
pytest --cov=pyafipws.pyfepdf tests/test_pyfepdf.py --cov-report=term-missing -vvv

for the wsltv.py module ---->

I found a typo and fixed it hoping the test case should pass

but still getting the same output

Checklist

• Classes, Variables, function and methods logic ok
• Comments written explaining what the code does
• All python code is PEP8 compliant (run black .)
• No lint issues (run flake8)
• Test coverage with pytest implemented
• Reviewers assigned (at least 1 mentor)

Manual test evidence

(attach command-line examples, execution output & logs, etc.)