Redmine

http://www.redmine.org/plugins/redmine_charts2,I follow the guide

For Redmine 2.1.x - 2.3.x

$ cd {REDMINE_ROOT}
$ git clone git://github.com/pharmazone/redmine_charts2 plugins/redmine_charts2
$ cd plugins/redmine_charts2
$ git co redmine21

Migrate database.

$ rake redmine:plugins RAILS_ENV=production

I use bitnami redmine 2.3.2 under windows, this command "git clone git://github.com/pharmazone/redmine_charts2 plugins/redmine_charts2" is successful, but git co redmine21 failed,the error message can been seen in the attachment, and if I skip "git co redmine21", direcly migrate database, error message is:

*D:\BitNami\redmine-2.3.2-0\apps\redmine\htdocs\plugins>rake redmine:plugins RAIL
S_ENV=production
(in D:/BitNami/redmine-2.3.2-0/apps/redmine/htdocs)
D:/BitNami/redmine-2.3.2-0/ruby/lib/ruby/gems/1.9.1/gems/watchr-0.7/lib/watchr.r
b:111: Use RbConfig instead of obsolete and deprecated Config.
rake aborted!
uninitialized constant OpenFlashChart::Base

Tasks: TOP => redmine:plugins:migrate => environment
(See full trace by running task with --trace) *

Anyone who konws how to solve the issue? And is there any other chart plugin to recommend for show issue charts.