fix(config): unify the handling of boolean environment variables

[Masterchen09]

Only a small fix here, but also see this PR for more information.

[github-actions[bot]]

Unit Test Results (build & test)

61 tests  ±0   61 :heavy_check_mark: ±0   4s :stopwatch: -1s   1 suites ±0     0 :zzz: ±0    1 files   ±0     0 :x: ±0 

Results for commit 66ae39cf. ± Comparison against base commit 1bc7124c.

:recycle: This comment has been updated with latest results.