fix: don't mutate original object in unset

[juanjoDiaz]

Fix small issue introduced in #496 which might modify the original data

[martinfrancois]

Consider adding a unit test which makes a deep copy before running parse, then compare the input to parse with the deep copy from before (checking for equality), to prevent regressions in the future 😃

[coveralls]

Coverage remained the same at 100.0% when pulling a0f3ef4 on juanjoDiaz:fix_unset_v5 into b071eb1 on zemirco:v5.

[martinfrancois]

Thanks for merging @knownasilya , is there a chance we can have a release soon, so we can get rid of our workaround that's in place for the moment?

[knownasilya]

Released

[martinfrancois]

Thanks a lot! 👍