Can move from one milestone to another a closed item

Part of story #7511 PlanningV2 - Drag'nDrop backlog items

Change-Id: Idfeff7e15dc46ad9a546541fbba63ceab930aae5
Merge commit 'refs/changes/44/3344/3' of ssh://gerrit.tuleap.net:29418/tuleap into tuleap-stable-master

* ssh://gerrit.tuleap.net:29418/tuleap:
  Can move from one milestone to another a closed item

Change-Id: I8545acfbd26bb05ec8fd331823a97d1a41e59789
This is Tuleap 7.7.99.75

Change-Id: I2a2f7348862e3d30ebb09255136674ced19b7816