Add LDAP users button disabled

[mariosm1]

Describe the bug
After upgrading to 8.1.2, existing users are able to log in using ldap credentials, but the button to add new LDAP users under Administration -> Users is disabled.

To Reproduce
Steps to reproduce the behavior:

1. Set up an 8.1.2 instance
2. Configure LDAP in the config.xml
3. Try to add a new LDAP user from your chosen directory

Expected behavior
The Add LDAP users button should be enabled when LDAP is configured

[natechadwick]

@matomario8 Was able to reproduce this on 8.1.3 dev branch, Server Admin is unaffected but the CMS UI user import feature is not enabling like it should.

[natechadwick]

The problem appears to be in the the config.xml the DirectorySet name must start with DirectorySet:

<PSXDirectorySet name="DirectorySetLDAP">

You can have more than one entry they just all need to start with the DirectorySet keyword in order to be picked up as LDAP catalogers.