Broken URLs in notifications if $base_url is not set in settings.php

Hi guys,

Awesome module. Thanks for the great work!

I usually set the $base_url in settings.php even though the instructions say it's optional. In this case, I'm in the process of moving a site to a new IP address so commented out the $base_url line so I could test the site in its new home.

But I noticed that the email notifications started coming with broken links. Here's a sample:

| Link: http:///event/4609/altiris-midwest-user-group-meeting
| Direct unsubscribe link (content type):
| http:///s/del/node/nid/4609/-1/9046/003ddc8c082fc06b329a7b798583823e
| --------------------------------------------------------------------
| This is an automated message. Please do NOT reply to the sender address!
| To manage your subscriptions go to
| http:///user/9046/subscriptions