LDAP attribute names should not be case-sensitive

<img width="328" height="110" alt="Image" src="https://github.com/user-attachments/assets/c14ef8d1-cde1-4b6b-8259-bce8149c73db" />

If cn is changed to CN, whole integration stops working.

