nay good sir. I do believe it's correct:

[redis]
server_ip   = 127.0.0.1
server_port = 6379

And adding a debug line:

    if ( config.redis ) {
        self.logdebug('Using config values from karma.ini');
        redis_ip = config.redis.server_ip || '127.0.0.1';
        redis_port = config.redis.server_port || '6379';
    };

Seems to agree with me:

[DEBUG] [-] [karma] Using config values from karma.ini