Request #5788: Fix for cxannot submit artifact when in HTML edit mode with 'Required' flag set

Change-Id: Icb4129b82ddccf6b584ef4fbe698e32659d6ea02
Merge commit 'refs/changes/98/1598/4' of http://gerrit.tuleap.net/tuleap into HEAD

* http://gerrit.tuleap.net/tuleap:
  Request #5788: Fix for cxannot submit artifact when in HTML edit mode with 'Required' flag set

Change-Id: I3933483b78d33f3ea7530d3a4e51859c84564315
This is Tuleap 6.8.99.26

Change-Id: I4b82dc9f54753549f474848316c06f155bf90874