Request #6089: Fatal error when removing user as project member (MW)

Change-Id: Ibd18f1f8addeb3b2bd15f1d5f5ee33f69dc4e9ac
Merge commit 'refs/changes/26/1826/1' of http://gerrit.tuleap.net/tuleap into HEAD

* http://gerrit.tuleap.net/tuleap:
  Request #6089: Fatal error when removing user as project member (MW)

Change-Id: I3f7996d32cab0d9208e567d9a1e7e58e0de6d5df
This is Tuleap 6.9.99.53

Change-Id: I95593ddf5f3d186ddd45b9086cff6965d69afdc6