default username is fixed. It's okay for amazon linux, but how about ubuntu?

Hey guys,

When I use the plugin, the default username is fixed to ec2-user . And in rundeck, all the ec2 nodes appear like ec2-user@public_ip. It's okay for amazon linux. But when I use ubuntu as ec2, it becomes a problem. So , how can I set up for both ec2-user and ubuntu user ? 