Update pl_PL app translation for 3.9.1

[pljones]

Hi @SeeLook,
We are getting ready for the 3.9.1 release. No further changes to translatable strings are currently planned for this release.

We would be happy if you updated the Jamulus software translations for pl_PL by 2022-10-08.

Please

• Update your fork from jamulussoftware/jamulus master and create a working branch
• Update translations using Qt Linguist in your fork,
• Commit and push your changes and reference this Issue,
• Open a Pull Request before 2022-10-08

Suggested commit and PR message:

Update pl_PL app translation for 3.9.1

Fixes #2871

Further documentation can be found in TRANSLATING.md.

Thanks for contributing to Jamulus!

[ann0see]

@SeeLook

As you might not use Weblate yet, please keep an eye on #2856
If you start translating without using Weblate, you might get conflicts.

[SeeLook]

Hi all there!
I was watching your discussion about utilize Wablate for the app translation and I was veeeeeerrrrry glad to see this is happening.
I started using it for my app some time back and it works really good.
So I was more happy to use it for Jamulus translation.without struggling with git.