Username set to __ when no preferred_username given in userinfo

INFO:ldf_adapter:init
INFO:ldf_adapter.name_generators:Potential username: []
WARNING:ldf_adapter.backend.local_unix:Name '[]' changed to '___' for shadow compatibilty
INFO:ldf_adapter:init done
INFO:ldf_adapter:Incoming request to 'deployed' user 'diana.gudu@kit.edu' (***@https%3A%2F%2Fiam.deep-hybrid-datacloud.eu%2F)
INFO:ldf_adapter:Creating group mytestcollab
WARNING:ldf_adapter:Issuer 'iam.deep-hybrid-datacloud.eu/' changed to 'iam.deep-hybrid-datacloud.eu-' for BWIDM compatibilty
INFO:ldf_adapter:self.service_user.name: ___
INFO:ldf_adapter:Creating user "___" for "***@https%3A%2F%2Fiam.deep-hybrid-datacloud.eu%2F"
INFO:ldf_adapter:starting while
INFO:ldf_adapter:initial try: ___
INFO:ldf_adapter:                             Using: ___
{
  "state": "deployed",
  "message": "User was created. Credentials ssh:deep_key were activated.",
  "credentials": {
    "ssh_user": "___",
    "ssh_host": "localhost",
    "commandline": "ssh ___@localhost",
    "description": "Local SSH Test Service",
    "login_help": "Login via `ssh {login_name}@{login_host}` using one of your deployed keys."
  }
}