Fix issue 962

[EmmaRenauld]

Quick description

Fixes issue #962

Type of change

Check the relevant options.

• [x] 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)

...

Checklist

• [x] My code follows the style guidelines of this project (run autopep8)
• [ ] I added relevant citations to scripts, modules and functions docstrings and descriptions
• [x] 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
• [x] My changes generate no new warnings
• [ ] I moved all functions from the script file (except the argparser and main) to scilpy modules
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 67.09%. Comparing base (377bed3) to head (0ad37be).

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #963 +/- ## ========================================== + Coverage 66.98% 67.09% +0.10% ========================================== Files 396 396 Lines 21411 21412 +1 Branches 3253 3253 ========================================== + Hits 14343 14367 +24 + Misses 5752 5727 -25 - Partials 1316 1318 +2 ``` | [Components](https://app.codecov.io/gh/scilus/scilpy/pull/963/components?src=pr&el=components&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | Coverage Δ | | |---|---|---| | [Scripts](https://app.codecov.io/gh/scilus/scilpy/pull/963/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | `68.12% <100.00%> (+0.04%)` | :arrow_up: | | [Library](https://app.codecov.io/gh/scilus/scilpy/pull/963/components?src=pr&el=component&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=scilus) | `65.50% <ø> (+0.20%)` | :arrow_up: |