SupAnn composite attributes do not remove values when last value is removed

When removing the last value of a supann composite attribute, like supannEtuInscription, individual values are not correctly removed.

linked to https://gitlab.opensides.be/telecomsudparis/Migration-FusionDirectory-OpenLDAP/-/issues/105

changed milestone to %FusionDirectory 1.4

added Bugs PJ1801-0146 plugin-supann labels

mentioned in commit 0a92f23c

added 30m of time spent at 2020-04-29

added To Be Tested label

changed the description

I just tested on demo-dev and it look right now.

I added supannEtuInscription and removed it later while checking the LDAP tab.

added 35m of time spent at 2020-05-04

removed To Be Tested label

closed

added Fixed label

removed Bugs label