Fix request #7234 tracker_ artifact_ changeset test fails on master

This is due to email_gateway feature and refactoring on this

Change-Id: I8893fce20dd15ff14fab083cc9a5b3d8a033b8eb
Merge commit 'refs/changes/79/2779/2' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  Fix request #7234 tracker_ artifact_ changeset test fails on master

Change-Id: Ibc37c30b470e5559be64a183b67795654892d3b8
This is Tuleap 7.2.99.52

Change-Id: I3dd8757b4aa85af7d90c3aee847b8aad2d54a430