commands do not work with `--profile` different from the default one

Hi,

I was having difficulties making the wrapper work while specifying a different profile using the `--profile` flag
the following commands were all issued in quick succession

```
~/somefolder > which aws
aws: aliased to aws-mfa-secure session
```

no profile - working - I already entered my mfa token earlier today, default profile is not profile123:
```
~/somefolder > aws s3 ls s3://some-bucket-name/

```

with --profile - not working
```
~/somefolder > aws --profile profile123 s3 ls s3://some-bucket-name/

An error occurred (AccessDenied) when calling the ListObjectsV2 operation: Access Denied
```

export AWS_PROFILE instead of --profile - now it's working - notice requesting the MFA code which --profile didn't
```
~/somefolder > export AWS_PROFILE=profile123
~/somefolder > aws s3 ls s3://some-bucket-name/
Please provide your MFA code:

Reproduce the issue with the shown `aws --profile profile123 s3 ls` and `AWS_PROFILE=profile123 aws s3 ls` commands, then trace how aws-mfa-secure handles the `--profile` flag versus the environment variable. Done means both forms request MFA as needed and successfully list the bucket contents.

Written by the indexing model from the issue text.