Can't start ejabberd 2.1.10 with mod_global_roster

I have been using ejabberd 2.1.10 and trying to include mod_global_roster (https://github.com/bob-p/mod_global_roster).

Here is the error that happens when trying to start ejabberd

Any ideas ?

=INFO REPORT==== 2012-02-09 15:34:09 ===
D(<0.256.0>:ejabberd_captcha:432) : The option captcha_cmd is not configured, but some module wants to use the CAPTCHA feature.

=INFO REPORT==== 2012-02-09 15:34:09 ===
I(<0.36.0>:ejabberd_rdbms:37) : ejabberd has not been compiled with relational database support. Skipping database startup.

=ERROR REPORT==== 2012-02-09 15:34:09 ===
C(<0.36.0>:gen_mod:75) : Problem starting the module mod_global_roster for host "localhost"
options: [{key,"Chat:online:"},
{redis_host,"localhost"},
{redis_port,6379},
{redis_db,0}]
error: undef

=ERROR REPORT==== 2012-02-09 15:34:09 ===
C(<0.36.0>:gen_mod:80) : ejabberd initialization was aborted because a module start failed.