unable to login - /var/lib/gems/1.9.1/gems/munin2graphite-0.2.0/lib/graphite/base.rb:24:in authenticate': undefined method first' for nil:NilClass (NoMethodError)

[innovia]

using munin 2.0.10 on server
using munin-node 2.0.11-1.1 on node

trying to run on node
munin2graphite /etc/munin/munin2graphite.conf

fails with:
/var/lib/gems/1.9.1/gems/munin2graphite-0.2.0/lib/graphite/base.rb:24:in authenticate': undefined methodfirst' for nil:NilClass (NoMethodError)

the issue is:

1. i have a basic http auth on the graphite web app
2. I have a user created inside the graphite web by using the graphite_web_address/admin

and i can't get it to work

my config:
carbon_hostname=my_graphite_server
carbon_port=2003

Graphite endpoint

The url of the grphite-web application this is used to config the graphs

graphite_endpoint=http://http_user:http_passwd@my_graphite_server:80

prefix for the metrics usually, the user name have to be put as a prefix

graphite_prefix=munin
graphite_user=(user from django admin interface created)
graphite_password=(password of user from django interface created)

The period for sending the metrics

its format is the one of rufus-scheduler

scheduler_metrics_period=1m
scheduler_graphs_period=1m

The munin node hostname and its port

munin_hostname=localhost
munin_port=4949

[innovia]

seems like there's no basic http auth option, and because my graphite has also basic http auth on top i can't login