fix(ldap): read the link before running delete

Hello,

According to the "force" argument, If true, then delete and replace an existing LDAP link if one exists.", Which means that if the link exists, it will delete it and create it, but if don't exists, it should only create it.

If it's not the desired change, another MR could be useful to clarify this part 😄

PS: this MR only apply on EE and not CE