Request #6197 : spinner stays if response is 500

Change-Id: Ia67ee9726e86640173324c5d85a6d2fa15156206
Merge commit 'refs/changes/13/1913/2' of http://gerrit.tuleap.net/tuleap into HEAD

* http://gerrit.tuleap.net/tuleap:
  Request #6197 : spinner stays if response is 500

Change-Id: Ib1c69d7b0da3672585cc56fa1c9771fd73726589
This is Tuleap 6.10.99.20

Change-Id: I15bf0cd987675e54b17899ee22ea3b44460d33dd