Some special characters prevent artifacts from being downloaded from the UI

Issue Summary

If there is a single artifact matching the copy patterns and contains % or ; in the file name, Bamboo will fail to download and will show a "Page not found" error

Steps to Reproduce

1. Set a script task with the following command:

   touch example%test.war

2. Create an artifact with the following copy pattern */.war
3. Run a build
4. On the build results go to artifacts and try to download

Expected Results

The artifact downloads.

Actual Results

Workaround

Set a script task to create an artifact matching the same copy pattern. If there is more than one artifact the following screen will be shown and the artifact file will be downloadable: