Fix for #4465 -- earlier "feature" patch broke ldap

The patch for #3904 should not have been accepted; it's buggy and the use case
(supporting having nodes in ldap more than once with the same name but distinct
records) is ill-conceived.

This commit reverts the patch (a7884b47) and the previous attempt to fix it
(e6709da4), restoring the old (0.25.x) behaviour.