fix sla #4627 Issue when download files bigger than memory_limit

Change-Id: Ic1c68c1074f56011315796f56213687a1a7685f0
Merge commit 'refs/changes/16/716/5' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  fix sla #4627 Issue when download files bigger than memory_limit

Change-Id: I943b60ab16a6caa9bfbb3dcaf54b288876ce1536
This is Tuleap 6.3.99.11

Change-Id: Ie147e35f8f20962d8f3d8cea63ba0e0dc5a3e33c