Add LDAP to Icingaweb2

[ShowMeYourSkil (David Franzen)]

@nicolas

sadly was not my solution, but i tested it with the following result:

Have you installed the certificate on the Icinga host and updated the CA store? That is, does the Icinga server know the certificate for LDAPS.

I had a similar strange problem last time
See here:

Can't contact LDAP server

New knowledge: I import the RootCA successfully. The first Validate Configuration check in Icinga is successful and the second one is not.