relicense `shootout-k-nucleotide.rs` to the shootout license

[TeXitoi]

See #14248

I propose to change the license of shootout-k-nucleotide.rs

Non trivial contributors:

• @pcwalton: OK
• @alexcrichton: OK
• @TeXitoi: OK

Contributors appearing in git blame that are trivial (trivial update due to language changes):

• @richo: OK
• @thestinger: waiting for response
• @huonw: OK

Contributors with removed and trivial contributions are not considered.

For the persons that are not in "OK" state, please respond to this issue saying:

I agree to relicense any previous contributions to http://github.com/rust-lang/rust according to the term of the Computer Language Benchmarks Game license (http://benchmarksgame.alioth.debian.org/license.php)

Then, I'll propose the corresponding PR.

Thanks.

[huonw]

I agree to relicense any previous contributions to http://github.com/rust-lang/rust according to the term of the Computer Language Benchmarks Game license (http://benchmarksgame.alioth.debian.org/license.php)

(I took the liberty of changing mozilla to rust-lang.)

[TeXitoi]

@thestinger ping

[brson]

@TeXitoi let's land this anyway.