Fix req #6071. Cannot delete x-refs in artifact. Choosing to not show x-refs in modal view.

Change-Id: I992d72a6ebc8b003d2b85c0a1a0c1688408669a1
Merge commit 'refs/changes/23/1823/1' of http://gerrit.tuleap.net/tuleap into HEAD

* http://gerrit.tuleap.net/tuleap:
  Fix req #6071. Cannot delete x-refs in artifact. Choosing to not show x-refs in modal view.

Change-Id: I204d0e11a2fbc9989cf2c337ad0f065f90635545
This is Tuleap 6.9.99.50

Change-Id: I594ccb04ad42d3423de96a5fee7f43f211cfaf2a