remove karaf.admin.role = admin from etc/system.properties

from conversation Josef Ludvicek <=> Freeman Fang

What purpose has entry karaf.admin.role = admin in etc/system.properties?

This is unnecessary now after we introduced RBAC in Apache Karaf as each username should be associated with some role explicitly anyway. It was used to specify a default role if you only have username=password in etc/users.properties before RBAC available. Please create a jira so we can remove it from system.properties