tasks #6904: mediawiki admins can access private projects' mediawikis

Change-Id: I95ac6f69acd8e5dbe5a80db7792409946821dc72
Merge commit 'refs/changes/67/2467/4' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  tasks #6904: mediawiki admins can access private projects' mediawikis

Change-Id: I6e2054222b48a8ee6987d692a2a130e17ad70ea3
This is Tuleap 7.0.99.42

Change-Id: Iee10644eaae86ae2ec7434ca11e785f6727f4175