Custodia uninstall: Don't fail when LDAP is down
    
    The Custodia instance is removed when LDAP is already shut down. Don't
    fail and only remove the key files from disk. The server_del command
    takes care of all Custodia keys in LDAP.
    
    https://pagure.io/freeipa/issue/7318
    
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>