story #7629 Mediawiki is taken in account in project disk usage

Change-Id: I989e124388bb4b89c63ce8ae3f7b9a8614a3fd26
Merge commit 'refs/changes/43/3243/4' of ssh://gerrit.tuleap.net:29418/tuleap into tuleap-stable-master

* ssh://gerrit.tuleap.net:29418/tuleap:
  story #7629 Mediawiki is taken in account in project disk usage

Change-Id: I1bec9b7c01438f2cb1aff21be51345d137a5c1be
This is Tuleap 7.7.99.10

Change-Id: I1e4188cef93b1ae13bb2c9eb1df81d6c6761a6ee