Re-add AWS_PROFILE env var

[lhavel]

I had an issue using AWS_PROFILE env var instead of AWS_DEFAULT_PROFILE with aws-cli-js 2.2.2.
I had a look at the code and realized that only AWS_DEFAULT_PROFILE was listed in env vars (index.js).
Although a PR has been merged before that release to add AWS_PROFILE... But it looks like it was kind of reverted?!

Can you add it back to the list of env vars?

[mattqs]

fixed in
https://github.com/Quobject/aws-cli-js/releases/tag/2.2.3