Update Polish translation (DEX357)

[alfrix]

Guidelines

1. Rebase before opening a pull request
2. If you are sending several unrelated fixes or features, use a branch and a separate pull request for each
3. If possible try squashing everything in a single commit. This is particularly beneficial in the case of feature merges since it allows easy bisecting when a problem arises

Description

[Description of the pull request, detail any issues you are fixing or any features you are implementing]

Related Issues

[Any issues this pull request may be addressing]

Related Pull Requests

[Any other PRs from related repositories that might be needed for this pull request to work]

Reviewers

[If possible @mention all the people that should review your pull request]