Trac importer does not use Trac's latest attachment path arrangement

Trac has changed the path for attachments, somewhere around 0.13 or 1.0...

It is now:
files/attachments/ticket/[first 3 digits of ticket id hash]/[full ticket id hash]/[filename hash].[original filename extension]

example for an attachment called "resize-error.png" to ticket #1189:
files/attachments/ticket/fdc/fdc01209f90eda589f0453b7e29e0114923ecd8b/c938eb2e1942386a45b1b8cdfce27a9f3d00f06f.png

This bug causes all errors for every ticket with an attachment when importing tickets from Trac to JIRA.