http:HTTPBasicAuth: Help string reference to not defined namevar

[frlan]

Help text says:

    Usage::

        from batou_ext.http import HTTPBasicAuth

        self += batou_ext.http.HTTPBasicAuth(
            "myauth",
            username="joe",
            password="secret",
            basic_auth_string="joe:$apr1$Ma0Fc6pW$Kl5dV4ecBXH12gDieRHVq.")

env_name, which this is referring to, is not defined as namevar leading into

Traceback (simplified, most recent call last):
  File "/xxx/deployment/components/mail/component.py", line 19, in configure
    self += batou_ext.http.HTTPBasicAuth(
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/xxx/deployment/.appenv/b8144391/lib/python3.11/site-packages/batou/component.py", line 216, in __init__
    raise ValueError("Namevar is undefined for this component.")