Can't create attachement when installed the plugin uses AttachmentListener and changed the context path

I can't create attachment to Wikis when I installed the plugin uses AttachmentListener and changed the confluence's context path at conf/server.xml.

If I re-install the plugin again, I can attach the files and the plugin execute correctly.

I think user can't know why I can't attach the files. This is really problem.

I attached sample simple plugin project that implements only AttachmentListener.

Reproduction:

1. setup confluence
2. install attached plugin
3. attach file on some wikis
4. change context path
5. attach file on some wikis (can't attach the files)