Kerberos/test_login_kerberos.py: removed test_krb_user_ldap_mapping

The test was removed for several reasons:
1) The test was never really working. The only reason it was passing was
   because of sssd caching.
2) The test in order to work needs a lot of extra parameters in sssd
   configuration and there is neither the knowledge nor the time to
   invest in learning it.
3) The LDAP mapping is not really used in our days and we believe that
   the case the test is testing is very rare.

Kerberos/test_login_kerberos.py

@@ -182,31 +182,3 @@ def test_krb_user_su_correct_password(ipa_user, user_shell):
         user_shell.sendline("whoami")
         user_shell.expect_exact(ipa_user.username)
         user_shell.close()
-
-
-def test_krb_user_ldap_mapping(ipa_user, ipa_server, user_shell, sssd):
-    """Test for LDAP mapping of Kerberos user provided by IPA server"""
-    changes = ({"section": f"domain/{ipa_server.domain}",
-                "key": "id_provider",
-                "val": "ldap"},
-               {"section": f"certmap/{ipa_server.domain}/{ipa_user.username}",
-                "key": "matchrule",
-                "val": f"<SUBJECT>.*CN={ipa_user.username}.*"},
-               {"section": f"certmap/{ipa_server.domain}/{ipa_user.username}",
-                "key": "maprule",
-                "val": "(userCertificate;binary={cert!bin})"})
-    with sssd as conf:
-        for item in changes:
-            conf.set(key=item["key"],
-                     value=item["val"],
-                     section=item["section"])
-        conf.save()
-
-        run(["systemctl", "restart", "sssd"], sleep=5)
-
-        with Authselect(), ipa_user.card(insert=True):
-            cmd = f"su {ipa_user.username} -c 'whoami'"
-            user_shell.sendline(cmd)
-            user_shell.expect_exact(f"PIN for {ipa_user.username}:")
-            user_shell.sendline(ipa_user.pin)
-            user_shell.expect_exact(ipa_user.username)