Fix request #7624 Can no longer reply to an artifact by email

Change-Id: I6e28a665ccc11b65e878fab867b469089ece427e
request #7620 - Cannot add non LDAP user to project

Yes, it is not really beautiful, even a bit crappy.

Problem appears when you have a Tuleap user (non-ldap one) who has an
 homonym in your LDAP directory. When you add this user to a project,
 the LDAP plugin will find him in your LDAP and try to create an 
account for him but he already has one so the exception 
LDAP_UserNotCreatedException will be raised and the process of 
adding him to the project aborted.

A proper workaround would be to check upstream whether it is really a
 ldap user or not (PFUser class has such information) but the event 
used by the LDAP plugin does not seem to pass the user object thus 
preventing us to do this check beforehand.

This issue probably existed since a long time but without any impact 
as the check on the returned user prevented to launch any 
synchronization if LDAPPlugin wasn't able to create an account for
the user. Today, with the Exception raised, it still prevent 
synchronization but the throw also prevents the continued execution 
of the "add user to project" action.

Change-Id: I526e50be2157ea484e54e881bd55bb88af07b36d
Merge commit 'refs/changes/33/3233/5' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  request #7620 - Cannot add non LDAP user to project

Change-Id: Ibd04228a13c141003cf5484cbc0dc683de9ab56f
This is Tuleap 7.6.99.61

Change-Id: I41c8dd7377e7c5be867ee2f039a46858ac6705e4
Merge commit 'refs/changes/32/3232/1' of ssh://gerrit.tuleap.net:29418/tuleap into HEAD

* ssh://gerrit.tuleap.net:29418/tuleap:
  Fix request #7624 Can no longer reply to an artifact by email

Change-Id: If415a533aa9b609227410525c710601d0881edd3
This is Tuleap 7.6.99.62

Change-Id: Iade594a93e23451f123738d4edd50ddf64931a3d