Fix Arabic Iso Code from ara to arb

[greyblake]

@godofdream Thanks for the PR. I think the PR name opposite from what you intended to do.

I mean, you wanted to replace Arb with Ara, right?

I tried to investigate the topic. It looks like both ara valid ISO codes, however the scope is different.

https://iso639-3.sil.org/code_tables/639/data/a?page=1

I also ask my Egyptian friend regarding Arb VS Ara, he says:

I have never seen this "arb" word befire. I always notice "ara" in some websites

So generally I'm OK to accept the change if you confirm your intention to replace arb with ara. Thanks

[greyblake]

Thanks. The change is available in v0.11.0.