Throws an error if UID attribute is not present in Active Directory

If UID attribute is not present in active directory, below line throws an error as it doesn't find username.

IdentityServer4.LdapExtension/IdentityServer.LdapExtension/UserModel/ActiveDirectoryAppUser.cs

Line 131 in 7447e52

    
           Username = ldapEntry.getAttribute(ActiveDirectoryLdapAttributes.UserName.ToDescriptionString()).StringValue;

There's no magic ;). Usually I would say that you are supposed to know which attributes you have in your AD. That being said, the "username" is a normal attribute in a normal AD. If you are using OpenLdap, it may differ (based on schema).