Upgrade Status should not list itself

I think that Upgrade Status should not list itself in the report.

When planning for a major upgrade, we don't need to track if the Upgrade Status module as been ported to the new version. We only need to use this tool to see if the overall site is ready to be upgraded, not including this tool as well.

By the way, thank you for bringing up this fabulous tool. It already reported to me that one of my sites is ready to be upgraded to Drupal 6.