Fix request #6106 - Cannot add a new gerrit server

Regression introduced by commit e1f46a57

Change-Id: Ib2c9b0abf457787199af28055aba429b08ecdf23
Merge commit 'refs/changes/27/1827/1' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  Fix request #6106 - Cannot add a new gerrit server

Change-Id: I6b51e2cb73f83ab33938b9c15e3e3654ed574037
This is Tuleap 6.9.99.54

Change-Id: I2c6dcaa9676a27aef5a96e8b31cb475f988770c3