Fixed serverless deploy script

[amothic]

Fixed problem of referencing wrong variables

npm run deploy -- -r ap-northeast-1 --chime-sdk-media-pipelines-region us-east-1 -b chime-demo-bucket -s chime-demo-stack -a meeting

> amazon-chime-sdk-js-serverless-demos@0.1.0 deploy
> node ./deploy.js -r ap-northeast-1 --chime-sdk-media-pipelines-region us-east-1 -b chime-demo-bucket -s chime-demo-stack -a meeting

Amazon Chime SDK Media Pipelines does not support ap-northeast-1 (control region). Specify one of the following regions: ap-southeast-1, eu-central-1, us-east-1, us-west-2.
See https://docs.aws.amazon.com/chime-sdk/latest/dg/sdk-available-regions.html#sdk-media-pipelines for more information.