if type is any but null is only allow value

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (be58870) 98.58% compared to head (491b893) 98.58%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #315 +/- ## ======================================= Coverage 98.58% 98.58% ======================================= Files 9 9 Lines 496 496 Branches 190 190 ======================================= Hits 489 489 Misses 7 7 ``` | [Impacted Files](https://codecov.io/gh/mrjono1/joi-to-typescript/pull/315?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None) | Coverage Δ | | |---|---|---| | [src/parse.ts](https://codecov.io/gh/mrjono1/joi-to-typescript/pull/315?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL3BhcnNlLnRz) | `97.15% <100.00%> (ø)` | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None)

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[mrjono1]

I think i have found a better fix for this

[mrjono1]

allow will not work but valid will https://github.com/mrjono1/joi-to-typescript/pull/321