Don't use date_mod to keep user date of last LDAP sync.
For now, date_mod is changed on each LDAP sync.Will be usefull to have 2 dates
- date_mod (which will stored the date of last change, as usual)
- date_sync (which will store the date of last sync to avoid unusefull sync : compare with ldap update timestamp)
fix update + first step for Don't use date_mod to keep user date of last LDAP sync see #2579