Use propdel to remove all bugtraq related properties, starting at the root of your working copy, or wherever you ran the batch file from.
Make sure you run include the -R option since your propset command was also recursive, then commit and you should be done.
Another option is to use Windows Explorer -> TortoiseSVN -> Properties on the root directory folder, then multi-select the bugtrack properties, click Remove, then Recursive, then commit.