Using credential_process results in a 404 error

When using an external credential process get-remote-codecommit always returns a 404.

I'm using aws-vault to test this, but your credential_process could be a cat of a json file.

I'm using aws-vault to handle my credentials, this is my configuration:

```
# .aws/config

[profile codecommit]
region=eu-west-1
credential_process = aws-vault exec sandbox-profile --json

[profile tmp]
region=eu-west-1
output=json
```

I verified that aws-vault was working and the credentials where correct by using `sts get-caller-identity` and testing the aws-vault credential output in a temporary profile:

```
aws --profile codecommit sts get-caller-identity
{
"UserId": "AROAIR7P4ZLYKGYCEVD6M:1583408935234570000",
"Account": "XXXXXXXXXXX",
"Arn": "arn:aws:sts::XXXXXXXXXXX:assumed-role/ROLE_NAME/1583408935234570000"
}

aws-vault exec sandbox-profile --json
{"Version":1,"AccessKeyId":"ASIAUBJLRPEKAZ2K7YC4","SecretAccessKey":"XXX","SessionToken":"YYY","Expiration":"2020-03-05T12:10:05Z"}

cat >> ~/.aws/credentails <

Reproduce the failure with the shown AWS config and git clone commands, then trace how get-remote-codecommit handles credential_process credentials. Done means the codecommit profile works like the temporary profile and the repository clone succeeds without the 403 response.

Do mô hình lập chỉ mục viết ra từ nội dung của issue.