Update to python-ldap 3.0.0

Replace python3-pyldap with python3-ldap.

Remove some old code for compatibility with very old python-ldap.

Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>

ipapython/ipaldap.py

@@ -29,6 +29,7 @@ import contextlib
 import collections
 import os
 import pwd
+import warnings
 
 # pylint: disable=import-error
 from six.moves.urllib.parse import urlparse
@@ -76,6 +77,20 @@ TRUNCATED_ADMIN_LIMIT = object()
 DIRMAN_DN = DN(('cn', 'directory manager'))
 
 
+if six.PY2:
+    # XXX silence python-ldap's BytesWarnings
+    warnings.filterwarnings(
+        action="ignore",
+        message="Under Python 2, python-ldap uses bytes",
+        category=BytesWarning
+    )
+    warnings.filterwarnings(
+        action="ignore",
+        message="Received non-bytes value",
+        category=BytesWarning
+    )
+
+
 class _ServerSchema(object):
     '''
     Properties of a schema retrieved from an LDAP server.