Stats links for some custom fields do not work.

(from JRA-4981):

I created a filter which filters on a custom field. When have the Integrity
Checker cleanup the issues above I notice my filters (only the ones
filtering on custom fields) get removed. Also noticed when I create
statistics portlet based on the filter using the custom field, the
statistics show up fine, but if I click one of the links in the statistics
portlet I get an odd error message (don't have it handy right now).
Statistic portlets based on standard JIRA fields work fine.

The specific error message looks like this when I click on one of the
links in the statistics portlet based on a filter using a custom field:

HTTP Status 404 - /secure/$%7BurlPrefix%7D&pid=10891

type Status report
message /secure/$%7BurlPrefix%7D&pid=10891
description The requested resource (/secure/$%7BurlPrefix%7D&pid=10891) is
not available.

Apache Tomcat/4.1.29

I'm assuming the "$%7BurlPrefix%7D" or "

" is not getting set
with the actual URL. My guess is this URL should be something like
"IssueNavigator.jspa?reset=true". This basically renders most our
portlets based on filters almost useless since most our filters filter on
custom some custom fields.