Fix the streamline_id wrong size, harmonize double quote

[frheault]

Quick description

Errors due to empty bundles when they are present in the second tractogram provided to the CLI.

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Type of change

Check the relevant options.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Provide data, screenshots, command line to test (if relevant)

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Checklist

• My code follows the style guidelines of this project (run autopep8)
• I added relevant citations to scripts, modules and functions docstrings and descriptions
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I moved all functions from the script file (except the argparser and main) to scilpy modules
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[frheault]

This is where the important change is.

[codecov]

Codecov Report

❌ Patch coverage is 77.27273% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 72.91%. Comparing base (b604b99) to head (d3a2f03).

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1315      +/-   ##
==========================================
- Coverage   72.91%   72.91%   -0.01%     
==========================================
  Files         295      295              
  Lines       25453    25451       -2     
  Branches     3567     3567              
==========================================
- Hits        18560    18557       -3     
  Misses       5389     5389              
- Partials     1504     1505       +1     

Flag	Coverage Δ
smoketests	69.74% <77.27%> (-0.01%)	⬇️
unittests	14.28% <0.00%> (+<0.01%)	⬆️

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Components	Coverage Δ
Scripts	75.44% <ø> (+<0.01%)	⬆️
Library	69.88% <77.27%> (-0.03%)	⬇️

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