Cron Daemon Wget blocked

I've got nginx on Debian 7 without cpanel.

I am seting-up my Crontab like this:

*/45 * * * * wget "http://example.com/cron-url.php" >/dev/null 2>&1

The above cron is being blocked with 403 forbidden:

--2014-12-10 05:40:01--  http://example.com/cron-url.php
Connecting to xyz.xx.xx.xxx:80... connected.
HTTP request sent, awaiting response... 403 Forbidden
2014-12-10 05:40:01 ERROR 403: Forbidden.

After searching here and googling, I understand that my server is probably blocking wget. I had a look at my nginx configuration file and I think it should be due to this:

if ($http_user_agent ~* LWP::Simple|BBBike|wget) {
    return 403;
}

For cron command, I have to use the url to it and absolute link to script path doesn't work. Now, what do I do if I need to allow cron to work without getting blocked? I was thinking maybe I need to allow wget from my own server, but don't know how to do that with nginx. Can someone help me resolve this cron issue?