fix git cross-refs not recognized in followup comments

Change-Id: I3251fb0f2914d7673720ee81fb7dbe363d50f7be
Merge commit 'refs/changes/19/819/1' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  fix git cross-refs not recognized in followup comments

Change-Id: I395077328196413e84000282a33666eb7c8b274b
This is Tuleap 6.3.99.15

Change-Id: I48280afb34834f243add14fb159fd1ee4d6fb22d