{ca,kra}instance: drop redundant URI argument from ad-hoc ldap2 connections
    
    Use the default LDAP URI from api.env.ldap_uri instead of specifying a
    custom URI in the argument, as the custom URI is always the same as the
    default URI.
    
    Reviewed-By: Martin Babinsky <mbabinsk@redhat.com>
    Reviewed-By: Christian Heimes <cheimes@redhat.com>