ChangeLog: allow encoding of file paths for gitblit

This change allows to encode the file path portion of a url if the parameter `encodeFileUri` is set.
E.g.
http://example.org/repo.git/my/file.txt
becomes
http://example.org/repo.git/my%2Ffile.txt

This is currently required to support [Gitblit](http://gitblit.com/) in the changelog plugin