wondershaper: install ajenti plugin using just pip

The ajenti plugin installation script (setup.py) copy the required files
into /var/lib/ajenti/plugins/wondershaper.

See related source code https://github.com/migonzalvar/ajenti-plugin-wondershaper/compare/0.1.0...0.3

Issue: https://sugardextrose.org/issues/4640
wondershaper: fix typo
Merge pull request #35 from migonzalvar/issue4640-wondershaper-plugin-independent-2

Issue 4640: (wondershaper) install ajenti plugin using just pip