tasks #7264: Delete wiki index when there is no data doesn't throw any error

This task is part of story #7185 Search in existing wiki pages

Change-Id: I0a3a54f7da3dde311034aa264b231c99cd3376b7
tasks #7227 & tasks #7226: Catch and Update wiki service permissions change

Theses tasks are part of story #7185 Search in existing wiki pages

Change-Id: I068a90e1991d6f7e35e8a84fa45af4c19f0b6438
tasks #7267: When I reference an existing wiki page in docman, reindex it in docman, delete it from wiki index

This task is part of story #7185 Search in existing wiki pages

Change-Id: Ib239ce958964ed7fc7a921e59385f57074caa648
Merge commit 'refs/changes/11/2811/5' of ssh://gerrit.tuleap.net:29418/tuleap into tuleap-stable-master

* ssh://gerrit.tuleap.net:29418/tuleap:
  tasks #7267: When I reference an existing wiki page in docman, reindex it in docman, delete it from wiki index
  tasks #7227 & tasks #7226: Catch and Update wiki service permissions change
  tasks #7264: Delete wiki index when there is no data doesn't throw any error

Change-Id: Id4957c359bcb5c2c30557ab6a88d2e670375ef22
Tuleap 7.3.99.11

Change-Id: I84d390be28fd46ebcb1f2dc2bceec8a9e8c40b69