[freeipa PR#5998][opened] [Backport][ipa-4-6] extdom: return LDAP_NO_SUCH_OBJECT if domains differ

[rcritten]

   URL: https://github.com/freeipa/freeipa/pull/5998
Author: rcritten
 Title: #5998: [Backport][ipa-4-6] extdom: return LDAP_NO_SUCH_OBJECT if domains differ
Action: opened

PR body:
"""
This PR was opened automatically because PR #5991 was pushed to master and backport to
ipa-4-6 is required.
"""

To pull the PR as Git branch:
git remote add ghfreeipa https://github.com/freeipa/freeipa
git fetch ghfreeipa pull/5998/head:pr5998
git checkout pr5998