How to refactor the AWS credentials (`awsaccesskeyid` and `awssecretaccesskey`) out of the Backupninja's `/etc/backup.d/*.dup` configuration files?

Related questions:

Step 1

Step 2

Create /etc/backup.d/0-credentials.sh with the contents:

export AWS_ACCESS_KEY_ID='<…>'
export AWS_SECRET_ACCESS_KEY='<…>'

Step 3

Step 4

Step 5

Step 6

Remove awsaccesskeyid and awssecretaccesskey from /etc/backup.d/*.dup files.