This change modifies the search for user information so that when the Anonymous credentials are not configured, the credentials entered by the user attempting to log in are used to bind to the LDAP service in order to do the search.

I've tested this with our LDAP server, which is configured not to allow any anonymous search; I believe that I did not change the behavior for the case in which the anonymous credentials are configured (if I configure them, it does the same sequence of operations to the LDAP server, but since they don't work I cannot be 100% sure).