Update postinst

[mikramarc]

Proposed changes

Please explain the changes you made. Add pictures or videos to explain them better if appropriate.

Types of changes

What types of changes does your code introduce?

• Bugfix (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)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. This is a reminder of what we should look for before merging this code. I have:

• Read and follow the contributing guidelines.
• Checked that all tests pass with my changes
• Added tests (automatic or manual) that prove the fix is effective or that the feature works
• Added necessary documentation (if appropriate)
• Added the corresponding license to each file and add the current year of any one that you modified.
• Tested on real hardware (if appropriate)